JP7596537B2 - Communication method and apparatus - Google Patents

Description

This application claims priority to Chinese Patent Application No. 202110581012.8, entitled "Communication Method and Apparatus," filed with the State Intellectual Property Office of the People's Republic of China on May 26, 2021, and Chinese Patent Application No. 202110821657.4, entitled "Communication Method and Apparatus," filed with the State Intellectual Property Office of the People's Republic of China on July 20, 2021, both of which are incorporated herein by reference in their entireties.

This application relates to the field of communications technology, and in particular to communications methods and devices.

In existing wireless local area network (WLAN) communication systems, a multilink device capable of supporting simultaneous communication on multiple links is provided to improve transmission efficiency. The multilink device may include one or more stations. When the station is an access point (AP), the multilink device may be referred to as an AP multilink device. When the station is a non-access point station (non-AP STA), the non-AP STA may also be simply written as an STA, and the multilink device may also be referred to as an STA multilink device.

For each AP, based on the basic service set identifier (BSSID), an AP whose BSSID is a broadcasted BSSID may be referred to as a broadcasted AP, and an AP whose BSSID is an unbroadcasted BSSID may be referred to as an unbroadcasted AP.

When a STA currently associated with an AP in an AP multilink device is in a dormant state, the STA belongs to a non-AP multilink device, and the AP is performing a channel switch (in this case, the beacon frame transmitted by the AP on the link on which the AP operates carries elements related to the channel switch, or, if the AP is an untransmitted BSSID AP in the multi-BSSID set, the beacon frame transmitted by the transmitted AP corresponding to the AP carries elements related to the channel switch of the AP), another AP from the same AP multilink device (if the AP is an untransmitted BSSID AP in the multi-BSSID set, the other AP is a transmitted AP in the multi-BSSID set) may carry elements related to the channel switch of the AP in a management frame. STAs associated with another AP (belonging to the same non-AP multilink device as the STA associated with the AP) know that the AP is performing a channel switch. Thus, STAs belonging to the same non-AP multilink device know the information.

However, if that AP performs a channel switch before another AP belonging to the same AP multilink device transmits a management frame, that other AP (sometimes referred to as the reporting AP) does not carry any information about the channel switch of that AP. In other words, non-AP multilink devices cannot know that the AP has performed a channel switch.

In view of this, the embodiments of the present application provide a communication method and device to solve the technical problem that if an AP performs a channel switch before the transmitting AP transmits a management frame, the transmitting AP does not carry the parameter elements of the AP, and therefore, the STA associated with the AP cannot know that the AP has performed a channel switch.

According to a first aspect, an embodiment of the present application provides a communication method. The method includes: A first access point (AP) generates a management frame. The management frame includes a capability information field. The capability information field includes first indication information. The first indication information indicates whether another AP in the first AP multilink device has performed a channel switch. The first AP multilink device includes a first AP. The first AP transmits the management frame to a first station (STA).

Based on the first aspect, when transmitting a management frame, the first AP may carry the first indication information to indicate whether another AP in the first AP multilink device has performed a channel switch. In this way, the first STA associated with the first AP and belonging to the non-AP MLD determines whether another AP in the first AP multilink device has performed a channel switch based on the first indication information. If another AP in the first AP multilink device has performed a channel switch, the STA obtains the channel switch information of the AP that performed the channel switch. Thus, the STA that belongs to the same non-AP MLD and is associated with the AP that performed the channel switch (even if the STA is in a dormant state) knows that the AP associated with the STA has performed a channel switch, and knows about the channel switch information after the channel switch.

In a possible design, the capability information field further includes a first critical update flag signaling. The first critical update flag signaling indicates whether a critical parameter update value of an AP in the first AP multilink device changes. The value of the first critical update flag signaling is independent of whether a management frame transmitted by an AP in the first AP multilink device includes an element related to channel switching, or whether a management frame transmitted by an AP in the first AP multilink device does not include an element related to channel switching.

Based on this possible design, for the first AP multilink device, the value of the AP's critical parameter update value does not change regardless of whether the management frame transmitted by the AP includes an element related to channel switching. In other words, the value of the first critical update flag signaling does not change regardless of whether the management frame transmitted by the AP includes an element related to channel switching.

In a possible design, when any event occurs among the critical basic service set BSS parameter events corresponding to an AP in the first AP multilink device, the first AP adjusts the value of the AP's critical parameter update value.

In a possible design, the critical BSS parameter events include at least one of the following events: an enhanced distributed channel access EDCA parameter element is modified, a direct sequence spread spectrum DSSS parameter set element is modified, a high throughput HT operation element is modified, a wide bandwidth channel switching element is included, a wide bandwidth channel switching wrapper element is included, an operation mode notification element is included, a very high throughput VHT operation element is modified, a high efficiency HE operation element is modified, a broadcast target wake time TWT element is inserted, a BSS color change notification element is included, a multi-user MU EDCA parameter set element is modified, a spatial multiplexing parameter set element is modified, and an extremely high throughput EHT operation element is modified.

In a possible design, the critical BSS parameter events do not include any one of the following events: inclusion of a channel switch announcement element, inclusion of an extended channel switch announcement element, inclusion of a quiet element, and inclusion of a quiet channel element.

Based on the above three possible designs, compared with the 802.11ax standard, the events of including a channel switch announcement element, including an extended channel switch announcement element, including a quiet element, and including a quiet channel element are removed from the important BSS parameter events. In this way, the STA multilink device associated with the first AP multilink device does not obtain repeated elements regarding the AP's channel switch based on the RNR element and the multilink element in the management frame. This reduces the power consumption of the STA multilink device and saves air interface transmission opportunities.

In a possible design, the management frame further includes an untransmitted basic service set identifier BSSID field. The untransmitted BSSID field includes second indication information, the second indication information indicating whether another AP in the second AP multilink device has performed a channel switch. At least one AP in the second AP multilink device and the first AP belong to the same multi-BSSID set. The untransmitted BSSID field is in an untransmitted BSSID capabilities element in an untransmitted BSSID profile subelement in the multi-BSSID element. The untransmitted BSSID field may alternatively be referred to as an untransmitted BSSID capabilities field or may have another name.

Based on this possible design, when sending a management frame, the first AP may carry the second indication information to indicate whether another AP in the second AP multilink device has performed a channel switch. In this way, the first STA associated with the first AP and belonging to the non-AP MLD determines whether another AP in the second AP multilink device has performed a channel switch based on the second indication information. If another AP in the second AP multilink device has performed a channel switch, the STA obtains the channel switch information of the AP that performed the channel switch. Thus, the STA that belongs to the same non-AP MLD and is associated with the AP that performed the channel switch (even if the STA is in a dormant state) knows that the AP associated with the STA has performed a channel switch, and knows about the channel switch information after the channel switch.

In a possible design, the untransmitted BSSID field includes a second critical update flag signaling, and the second critical update flag signaling indicates whether a critical parameter update value of an AP in the second AP multilink device changes. The value of the second critical update flag signaling is independent of whether a management frame transmitted by an AP in the second AP multilink device includes an element related to channel switching, or the management frame transmitted by an AP in the second AP multilink device does not include an element related to channel switching.

Based on this possible design, for the second AP multilink device, the value of the AP's critical parameter update value does not change regardless of whether the management frame transmitted by the AP includes an element related to channel switching. In other words, the value of the second critical update flag signaling does not change regardless of whether the management frame transmitted by the AP includes an element related to channel switching.

In a possible design, when any of the critical BSS parameter events corresponding to an AP in the second AP multilink device occurs, the first AP adjusts the value of the AP's critical parameter update value.

Based on this possible design, compared with the 802.11ax standard, the events of including a channel switch announcement element, including an extended channel switch announcement element, including a quiet element, and including a quiet channel element are removed from the important BSS parameter events. In this way, the STA multilink device associated with the first AP multilink device does not obtain repeated elements regarding the AP's channel switch based on the RNR element and the multilink element in the management frame. This reduces the power consumption of the STA multilink device and saves air interface transmission opportunities.

According to a second aspect, an embodiment of the present application provides a first AP. The first AP may implement a function performed by the first AP in the first aspect or a possible design of the first aspect, and the function may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the function, for example, a processing module and a transceiver module. The processing module is configured to generate a management frame. The management frame includes a capability information field. The capability information field includes first indication information, and the first indication information indicates whether another AP in the first AP multilink device has performed channel switching. The first AP multilink device includes a first AP. The transceiver module is configured to transmit the management frame to a first station STA.

In a possible design, the capability information field further includes a first critical update flag signaling. The first critical update flag signaling indicates whether a critical parameter update value of an AP in the first AP multilink device changes. The value of the first critical update flag signaling is independent of whether a management frame transmitted by an AP in the first AP multilink device includes an element related to channel switching, or whether a management frame transmitted by an AP in the first AP multilink device does not include an element related to channel switching.

In a possible design, the processing module is further configured to adjust the value of the AP's critical parameter update value when any event among the critical basic service set BSS parameter events corresponding to the AP in the first AP multilink device occurs.

In a possible design, the critical BSS parameter events include at least one of the following events: an enhanced distributed channel access EDCA parameter element is modified, a direct sequence spread spectrum DSSS parameter set element is modified, a high throughput HT operation element is modified, a wide bandwidth channel switching element is included, a wide bandwidth channel switching wrapper element is included, an operation mode notification element is included, a very high throughput VHT operation element is modified, a high efficiency HE operation element is modified, a broadcast target wake time TWT element is inserted, a BSS color change notification element is included, a multi-user MU EDCA parameter set element is modified, a spatial multiplexing parameter set element is modified, and an extremely high throughput EHT operation element is modified.

In a possible design, the critical BSS parameter events do not include any one of the following events: inclusion of a channel switch announcement element, inclusion of an extended channel switch announcement element, inclusion of a quiet element, and inclusion of a quiet channel element.

In a possible design, the management frame further includes an untransmitted basic service set identifier BSSID field. The untransmitted BSSID field includes second indication information, and the second indication information indicates whether another AP in the second AP multilink device has performed a channel switch. At least one AP in the second AP multilink device and the first AP belong to the same multi-BSSID set.

In a possible design, the untransmitted BSSID field includes a second critical update flag signaling, and the second critical update flag signaling indicates whether a critical parameter update value of an AP in the second AP multilink device changes. The value of the second critical update flag signaling is independent of whether a management frame transmitted by an AP in the second AP multilink device includes an element related to channel switching, or the management frame transmitted by an AP in the second AP multilink device does not include an element related to channel switching.

In a possible design, the processing module is further configured to adjust the value of the AP's critical parameter update value when any of the critical BSS parameter events corresponding to the AP in the second AP multilink device occurs.

It should be noted that for a specific implementation of the first AP in the second aspect, reference is made to the operational functions of the first AP in the communication method provided in the first aspect or any one of the possible designs of the first aspect.

According to a third aspect, an embodiment of the present application provides a first AP. The first AP may be the first AP or a chip or system-on-chip in the first AP. The first AP may implement the functions performed by the first AP in the above-mentioned aspects or possible designs, and the functions may be implemented by hardware. In a possible design, the first AP may include a processor and a transceiver. The processor and the transceiver may be configured to support the first AP in implementing the functions in the first aspect or any one of the possible designs of the first aspect. For example, the processor may be configured to generate a management frame. The management frame includes a capability information field, the capability information field includes first indication information, and the first indication information indicates whether another AP in the first AP multilink device has performed a channel switch. The first AP multilink device includes the first AP. The transceiver may be configured to transmit the management frame to the first station STA. In yet another possible design, the first AP may further include a memory. The memory is configured to store computer-executable instructions and data necessary for the first AP. When the first AP operates, the transceiver and the processor execute the computer-executable instructions stored in the memory, thereby causing the first AP to perform a communication method according to the first aspect or any one of the possible designs of the first aspect.

For a specific implementation of the first AP in the third aspect, please refer to the operational functions of the first AP in the communication method provided in the first aspect or any one of the possible designs of the first aspect.

According to a fourth aspect, an embodiment of the present application provides a communication method. The method includes: A first station STA receives a management frame from a first access point AP. The management frame includes a capability information field. The capability information field includes first indication information, and the first indication information indicates whether another AP in the first AP multilink device has performed a channel switch. The first AP multilink device includes a first AP, and the STA multilink device includes a first STA. When the first indication information indicates that another AP in the first AP multilink device has performed a channel switch, the first STA obtains channel switch information of the AP that performs the channel switch, so that in the STA multilink device, a STA associated with the AP that performed the channel switch obtains the channel switch information.

Based on the fourth aspect, when transmitting a management frame, the first AP may carry the first indication information to indicate whether another AP in the first AP multilink device has performed a channel switch. In this way, the first STA associated with the first AP and belonging to the non-AP MLD determines whether another AP in the first AP multilink device has performed a channel switch based on the first indication information. If another AP in the first AP multilink device has performed a channel switch, the STA obtains the channel switch information of the AP that performed the channel switch. Thus, the STA that belongs to the same non-AP MLD and is associated with the AP that performed the channel switch (even if the STA is in a dormant state) knows that the AP associated with the STA has performed a channel switch, and knows about the channel switch information after the channel switch.

In a possible design, the capability information field further includes a first critical update flag signaling. The first critical update flag signaling indicates whether a critical parameter update value of an AP in the first AP multilink device changes. The value of the first critical update flag signaling is independent of whether a management frame transmitted by an AP in the first AP multilink device includes an element related to channel switching, or whether a management frame transmitted by an AP in the first AP multilink device does not include an element related to channel switching.

Based on this possible design, for the first AP multilink device, the value of the AP's critical parameter update value does not change regardless of whether the management frame transmitted by the AP includes an element related to channel switching. In other words, the value of the first critical update flag signaling does not change regardless of whether the management frame transmitted by the AP includes an element related to channel switching.

In a possible design, the value of the critical parameter update value of an AP in the first AP multilink device is adjusted based on the occurrence of any of the critical basic service set BSS parameter events corresponding to the AP.

In a possible design, the critical BSS parameter events include at least one of the following events: an enhanced distributed channel access EDCA parameter element is modified, a direct sequence spread spectrum DSSS parameter set element is modified, a high throughput HT operation element is modified, a wide bandwidth channel switching element is included, a wide bandwidth channel switching wrapper element is included, an operation mode notification element is included, a very high throughput VHT operation element is modified, a high efficiency HE operation element is modified, a broadcast target wake time TWT element is inserted, a BSS color change notification element is included, a multi-user MU EDCA parameter set element is modified, a spatial multiplexing parameter set element is modified, and an extremely high throughput EHT operation element is modified.

In a possible design, the critical BSS parameter events do not include any one of the following events: inclusion of a channel switch announcement element, inclusion of an extended channel switch announcement element, inclusion of a quiet element, and inclusion of a quiet channel element.

Based on the above three possible designs, compared with the 802.11ax standard, the events of including a channel switch announcement element, including an extended channel switch announcement element, including a quiet element, and including a quiet channel element are removed from the important BSS parameter events. In this way, the STA multilink device associated with the first AP multilink device does not obtain repeated elements regarding the AP's channel switch based on the RNR element and the multilink element in the management frame. This reduces the power consumption of the STA multilink device and saves air interface transmission opportunities.

In a possible design, the management frame further includes an untransmitted basic service set identifier BSSID field. The untransmitted BSSID field includes second indication information, and the second indication information indicates whether another AP in the second AP multilink device has performed a channel switch. At least one AP in the second AP multilink device and the first AP belong to the same multi-BSSID set.

In a possible design, when the second indication information indicates that an AP in the second AP multilink device has performed a channel switch, the first STA obtains channel switch information of the AP that performed the channel switch, so that in the STA multilink device, a STA associated with the AP that performed the channel switch obtains the channel switch information.

Based on the above two possible designs, when sending a management frame, the first AP may carry the second indication information to indicate whether another AP in the second AP multilink device has performed a channel switch. In this way, the first STA associated with the first AP and belonging to the non-AP MLD determines whether another AP in the second AP multilink device has performed a channel switch based on the second indication information. If another AP in the second AP multilink device has performed a channel switch, the STA obtains the channel switch information of the AP that performed the channel switch. Thus, the STA that belongs to the same non-AP MLD and is associated with the AP that performed the channel switch (even if the STA is in a dormant state) knows that the AP associated with the STA has performed a channel switch, and knows about the channel switch information after the channel switch.

In a possible design, the untransmitted BSSID field includes a second critical update flag signaling, and the second critical update flag signaling indicates whether a critical parameter update value of an AP in the second AP multilink device changes. The value of the second critical update flag signaling is independent of whether a management frame sent by an AP in the second AP multilink device includes an element related to channel switching, or the management frame sent by an AP in the second AP multilink device does not include an element related to channel switching.

Based on this possible design, for the second AP multilink device, the value of the AP's critical parameter update value does not change regardless of whether the management frame transmitted by the AP includes an element related to channel switching. In other words, the value of the second critical update flag signaling does not change regardless of whether the management frame transmitted by the AP includes an element related to channel switching.

In a possible design, the value of the critical parameter update value of an AP in the second AP multilink device is adjusted based on the occurrence of any one of the critical BSS parameter events corresponding to the AP.

Based on this possible design, compared with the 802.11ax standard, the events of including a channel switch announcement element, including an extended channel switch announcement element, including a quiet element, and including a quiet channel element are removed from the important BSS parameter events. In this way, the STA multilink device associated with the first AP multilink device does not obtain repeated elements regarding the AP's channel switch based on the RNR element and the multilink element in the management frame. This reduces the power consumption of the STA multilink device and saves air interface transmission opportunities.

According to a fifth aspect, an embodiment of the present application provides a first STA. The first STA may implement a function performed by the first STA in the fourth aspect or a possible design of the fourth aspect, and the function may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the function, for example, a transceiver module and a processing module. The transceiver module is configured to receive a management frame from a first access point AP. The management frame includes a capability information field. The capability information field includes first indication information, and the first indication information indicates whether another AP in the first AP multilink device has performed a channel switch. The first AP multilink device includes the first AP, and the STA multilink device includes the first STA. When the first indication information indicates that another AP in the first AP multilink device has performed a channel switch, the processing module is configured to obtain channel switch information of the AP that performs the channel switch, whereby in the STA multilink device, a STA associated with the AP that performed the channel switch obtains the channel switch information.

In a possible design, the capability information field further includes a first critical update flag signaling. The first critical update flag signaling indicates whether a critical parameter update value of an AP in the first AP multilink device changes. The value of the first critical update flag signaling is independent of whether a management frame transmitted by an AP in the first AP multilink device includes an element related to channel switching, or whether a management frame transmitted by an AP in the first AP multilink device does not include an element related to channel switching.

In a possible design, the value of the critical parameter update value of an AP in the first AP multilink device is adjusted based on the occurrence of any of the critical basic service set BSS parameter events corresponding to the AP.

In a possible design, the critical BSS parameter events include at least one of the following events: an enhanced distributed channel access EDCA parameter element is modified, a direct sequence spread spectrum DSSS parameter set element is modified, a high throughput HT operation element is modified, a wide bandwidth channel switching element is included, a wide bandwidth channel switching wrapper element is included, an operation mode notification element is included, a very high throughput VHT operation element is modified, a high efficiency HE operation element is modified, a broadcast target wake time TWT element is inserted, a BSS color change notification element is included, a multi-user MU EDCA parameter set element is modified, a spatial multiplexing parameter set element is modified, and an extremely high throughput EHT operation element is modified.

In a possible design, the critical BSS parameter events do not include any one of the following events: inclusion of a channel switch announcement element, inclusion of an extended channel switch announcement element, inclusion of a quiet element, and inclusion of a quiet channel element.

In a possible design, the management frame further includes an untransmitted basic service set identifier BSSID field. The untransmitted BSSID field includes second indication information, and the second indication information indicates whether another AP in the second AP multilink device has performed a channel switch. At least one AP in the second AP multilink device and the first AP belong to the same multi-BSSID set.

In a possible design, when the second indication information indicates that an AP in the second AP multilink device has performed a channel switch, the processing module is further configured to obtain channel switch information of the AP that performed the channel switch, whereby, in the STA multilink device, a STA associated with the AP that performed the channel switch obtains the channel switch information.

In a possible design, the untransmitted BSSID field includes a second critical update flag signaling, and the second critical update flag signaling indicates whether a critical parameter update value of an AP in the second AP multilink device changes. The value of the second critical update flag signaling is independent of whether a management frame transmitted by an AP in the second AP multilink device includes an element related to channel switching, or the management frame transmitted by an AP in the second AP multilink device does not include an element related to channel switching.

In a possible design, the value of the critical parameter update value of an AP in the second AP multilink device is adjusted based on the occurrence of any one of the critical BSS parameter events corresponding to the AP.

It should be noted that for a specific implementation of the first STA in the fifth aspect, reference should be made to the operational functions of the first STA in the communication method provided in the fourth aspect or any one of the possible designs of the fourth aspect.

According to a sixth aspect, an embodiment of the application provides a first STA. The first STA may be the first STA or a chip or system-on-chip in the first STA. The first STA may implement the functions performed by the first STA in the above-mentioned aspects or possible designs, and the functions may be implemented by hardware. In a possible design, the first STA may include a transceiver and a processor. The transceiver and the processor may be configured to support the first STA in implementing the functions in the fourth aspect or any one of the possible designs of the fourth aspect. For example, the transceiver is configured to receive a management frame from a first access point AP. The management frame includes a capability information field. The capability information field includes first indication information, and the first indication information indicates whether another AP in the first AP multilink device has performed a channel switch. The first AP multilink device includes the first AP, and the STA multilink device includes the first STA. When the first indication information indicates that another AP in the first AP multilink device has performed a channel switch, the processor is configured to obtain channel switch information of the AP that performs the channel switch, so that in the STA multilink device, a STA associated with the AP that performed the channel switch obtains the channel switch information. In yet another possible design, the first STA may further include a memory. The memory is configured to store computer-executable instructions and data necessary for the first STA. When the first STA operates, the transceiver and the processor execute the computer-executable instructions stored in the memory, so that the first STA performs a communication method according to any one of the fourth aspect or possible designs of the fourth aspect.

For a specific implementation of the first STA in the sixth aspect, please refer to the operational functions of the first STA in the communication method provided in the fourth aspect or any one of the possible designs of the fourth aspect.

According to a seventh aspect, an embodiment of the present application provides a communication method. The method includes: After a first access point AP generates a management frame and an AP in the first AP multilink device performs a channel switch, the management frame includes an ML element, the ML element includes channel switch information of the AP that performed the channel switch, and the ML element is until the next delivery traffic indication map DTIM beacon frame sent by the first AP. The first AP multilink device includes a first AP. The first AP transmits the management frame to a first station STA.

Based on the seventh aspect, when the first AP transmits a management frame, the channel switch information of the AP that performed the channel switch in the first AP multilink device may be indicated by carrying the channel switch information in the ML element. In this way, the first STA associated with the first AP determines the channel switch information of the AP that performed the channel switch based on the ML element, and the STA associated with the AP that performed the channel switch knows that the AP associated with the STA has performed the channel switch and knows about the channel switch information after the channel switch.

In a possible design, after an AP in the second AP multilink device performs a channel switch, the ML element further includes channel switch information of the AP in the second AP multilink device that performed the channel switch, and the ML element is until the next DTIM beacon frame transmitted by the first AP, and at least one AP in the second AP multilink device and the first AP belong to the same multi-BSSID set.

Based on this possible design, when the first AP sends a management frame, the channel switching information of the AP that performed the channel switching in the second AP multilink device can be further indicated. In this way, the first STA associated with the first AP determines the channel switching information of the AP that performed the channel switching based on the ML element, and the STA associated with the AP that performed the channel switching knows that the AP associated with the STA has performed the channel switching, and knows about the channel switching information after the channel switching.

In possible designs, the channel switching information includes elements related to the channel switching, or the channel switching information includes a changed operating class and a changed channel number of the AP, or the channel switching information includes a changed channel number of the AP.

Based on this possible design, the channel switching information may include elements related to the channel switching, or may include the changed operating class and changed channel number of the AP. This is not limited.

In a possible design, the management frame further includes a channel switch count field. When the value of the channel switch count field is a first value, the channel switch count field indicates that a channel switch will occur immediately before the next target beacon transmission time, or when the value of the channel switch count field is a second value, the channel switch count field indicates that a channel switch will occur any time after the management frame is transmitted, or that a channel switch has occurred.

Based on the above possible design, unlike the 802.11ax standard, when an AP in the first AP multilink device performs a channel switch, and when the first AP transmits a management frame after the AP completes the channel switch, the channel switch information of the AP that performed the channel switch is still carried in the ML element of the management frame until the next DTIM beacon frame, so that the STA in the STA multilink device knows about the channel switch information of the AP that performed the channel switch. In this case, the value of the channel switch count field may be a second value to indicate that a channel switch occurs at any time after the management frame is transmitted, or that a channel switch has occurred.

According to an eighth aspect, an embodiment of the present application provides a first AP. The first AP may implement the functions performed by the first AP in the seventh aspect or a possible design of the seventh aspect, and the functions may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the functions, for example, a processing module and a transceiver module. The processing module is configured to generate a management frame, and after an AP in the first AP multilink device performs a channel switch, the management frame includes an ML element, and the ML element includes channel switch information of the AP that performed the channel switch, and the ML element is until the next delivery traffic indication map DTIM beacon frame transmitted by the first AP. The first AP multilink device includes a first AP. The transceiver module is configured to transmit the management frame to a first station STA.

In a possible design, after an AP in the second AP multilink device performs a channel switch, the ML element further includes channel switch information of the AP in the second AP multilink device that performed the channel switch, and the ML element is until the next DTIM beacon frame transmitted by the first AP, and at least one AP in the second AP multilink device and the first AP belong to the same multi-BSSID set.

In possible designs, the channel switching information includes elements related to channel switching, or the channel switching information includes a changed operating class and a changed channel number of the AP, or the channel switching information includes a changed channel number of the AP.

In a possible design, the management frame further includes a channel switch count field. When the value of the channel switch count field is a first value, the channel switch count field indicates that a channel switch will occur immediately before the next target beacon transmission time, or when the value of the channel switch count field is a second value, the channel switch count field indicates that a channel switch will occur any time after the management frame is transmitted, or that a channel switch has occurred.

It should be noted that for a specific implementation of the first AP in the eighth aspect, reference is made to the operational functions of the first AP in the communication method provided in the seventh aspect or any one of the possible designs of the seventh aspect.

According to a ninth aspect, an embodiment of the present application provides a first AP. The first AP may be the first AP or a chip or system-on-chip in the first AP. The first AP may implement the functions performed by the first AP in the aforementioned aspects or possible designs, and the functions may be implemented by hardware. In a possible design, the first AP may include a processor and a transceiver. The processor is configured to generate a management frame, and after an AP in the first AP multilink device performs a channel switch, the management frame includes an ML element, and the ML element includes channel switch information of the AP that performed the channel switch, and the ML element is until the next delivery traffic indication map DTIM beacon frame transmitted by the first AP. The first AP multilink device includes the first AP. The transceiver module is configured to transmit the management frame to the first station STA. In yet another possible design, the first AP may further include a memory. The memory is configured to store computer executable instructions and data necessary for the first AP. When the first AP operates, the transceiver and the processor execute computer-executable instructions stored in the memory, thereby causing the first AP to perform a communication method according to the seventh aspect or any one of the possible designs of the seventh aspect.

For a specific implementation of the first AP in the ninth aspect, please refer to the operational functions of the first AP in the communication method provided in the seventh aspect or any one of the possible designs of the seventh aspect.

According to a tenth aspect, an embodiment of the present application provides a communication method. The method includes: A first station STA receives a management frame from a first access point AP. The management frame includes an ML element, which includes channel switching information of an AP in the first AP multilink device that has performed a channel switch, until the first STA receives a next delivery traffic indication map DTIM beacon frame transmitted by the first AP. The first AP multilink device includes the first AP, and the STA multilink device includes the first STA. The first STA obtains the channel switching information based on the ML element, whereby a STA associated with the AP in the STA multilink device that has performed the channel switch obtains the channel switching information.

Based on the tenth aspect, when the first AP transmits a management frame, the channel switch information of the AP that performed the channel switch in the first AP multilink device may be indicated by carrying the channel switch information in the ML element. In this way, the first STA associated with the first AP determines the channel switch information of the AP that performed the channel switch based on the ML element, and the STA associated with the AP that performed the channel switch knows that the AP associated with the STA performed the channel switch and knows about the channel switch information after the channel switch.

In a possible design, the ML element further includes channel switch information of an AP in the second AP multilink device that performed the channel switch, and the ML element is until the first STA receives the next delivery traffic indication map DTIM beacon frame transmitted by the first AP, and at least one AP in the second AP multilink device and the first AP belong to the same multi-BSSID set.

Based on this possible design, when the first AP sends a management frame, the channel switching information of the AP that performed the channel switching in the second AP multilink device can be further indicated. In this way, the first STA associated with the first AP determines the channel switching information of the AP that performed the channel switching based on the ML element, and the STA associated with the AP that performed the channel switching knows that the AP associated with the STA has performed the channel switching, and knows about the channel switching information after the channel switching.

In possible designs, the channel switching information includes elements related to the channel switching, or the channel switching information includes a changed operating class and a changed channel number of the AP, or the channel switching information includes a changed channel number of the AP.

Based on this possible design, the channel switching information may include elements related to the channel switching, or may include the changed operating class and changed channel number of the AP. This is not limited.

In a possible design, the management frame further includes a channel switch count field. When the value of the channel switch count field is a third value, the channel switch count field indicates that a channel switch will occur immediately before the next target beacon transmission time, or when the value of the channel switch count field is a fourth value, the channel switch count field indicates that a channel switch will occur any time after the management frame is transmitted, or that a channel switch has occurred.

Based on the above possible design, unlike the 802.11ax standard, when an AP in the first AP multilink device performs a channel switch, and when the first AP transmits a management frame after the AP completes the channel switch, the channel switch information of the AP that performed the channel switch is still carried in the ML element of the management frame until the next DTIM beacon frame, so that the STA in the STA multilink device knows about the channel switch information of the AP that performed the channel switch. In this case, the value of the channel switch count field may be a second value to indicate that a channel switch occurs at any time after the management frame is transmitted, or that a channel switch has occurred.

According to an eleventh aspect, an embodiment of the present application provides a first STA. The first STA may implement a function performed by the first STA in the tenth aspect or a possible design of the tenth aspect, and the function may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the function, for example, a transceiver module and a processing module. The transceiver module is configured to receive a management frame from a first access point AP. The management frame includes an ML element, and the ML element includes channel switching information of an AP in the first AP multilink device that has performed a channel switch, and the ML element is until the first STA receives a next delivery traffic indication map DTIM beacon frame transmitted by the first AP. The first AP multilink device includes the first AP, and the STA multilink device includes the first STA. The processing module is configured to obtain channel switching information based on the ML element, whereby a STA associated with the AP in the STA multilink device that has performed a channel switch obtains the channel switching information.

In a possible design, the ML element further includes channel switch information of an AP in the second AP multilink device that performed the channel switch, and the ML element is until the first STA receives the next delivery traffic indication map DTIM beacon frame transmitted by the first AP, and at least one AP in the second AP multilink device and the first AP belong to the same multi-BSSID set.

In possible designs, the channel switching information includes elements related to the channel switching, or the channel switching information includes a changed operating class and a changed channel number of the AP, or the channel switching information includes a changed channel number of the AP.

In a possible design, the management frame further includes a channel switch count field. When the value of the channel switch count field is a third value, the channel switch count field indicates that a channel switch will occur immediately before the next target beacon transmission time, or when the value of the channel switch count field is a fourth value, the channel switch count field indicates that a channel switch will occur any time after the management frame is transmitted, or that a channel switch has occurred.

For a specific implementation of the first STA in the 11th aspect, please refer to the operational functions of the first STA in the communication method provided in the 10th aspect or any one of the possible designs of the 10th aspect.

According to a twelfth aspect, an embodiment of the present application provides a first STA. The first STA may be the first STA or a chip or system-on-chip in the first STA. The first STA may implement the functions performed by the first STA in the above-mentioned aspects or possible designs, and the functions may be implemented by hardware. In a possible design, the first STA may include a transceiver. The transceiver may be configured to support the first STA in implementing the functions in the tenth aspect or any one of the possible designs of the tenth aspect. For example, the transceiver may be configured to receive a management frame from a first access point AP. The management frame includes an ML element, and the ML element includes channel switching information of an AP that has performed a channel switch in the first AP multilink device, and the ML element is until the first STA receives a next delivery traffic indication map DTIM beacon frame transmitted by the first AP. The first AP multilink device includes the first AP, and the STA multilink device includes the first STA. The processor is configured to obtain channel switching information based on the ML element, whereby a STA associated with the AP that performed the channel switching, which is in the STA multilink device, obtains the channel switching information. In yet another possible design, the first STA may further include a memory. The memory is configured to store computer-executable instructions and data necessary for the first STA. When the first STA operates, the transceiver and the processor execute the computer-executable instructions stored in the memory, whereby the first STA performs a communication method according to any one of the tenth aspect or possible designs of the tenth aspect.

For a specific implementation of the first STA in the 12th aspect, please refer to the operational functions of the first STA in the communication method provided in the 10th aspect or any one of the possible designs of the 10th aspect.

According to a thirteenth aspect, a communication device is provided. The communication device includes one or more processors and one or more memories. The one or more memories are coupled to the one or more processors. The one or more memories are configured to store computer programs or instructions. The one or more processors are configured to execute the computer programs or instructions. When the one or more processors execute the computer programs or instructions, a communication method according to the first aspect or any one of the possible designs of the first aspect is performed, or a communication method according to the fourth aspect or any of the possible designs of the fourth aspect is performed, or a communication method according to the seventh aspect or any of the possible designs of the seventh aspect is performed, or a communication method according to the tenth aspect or any of the possible designs of the tenth aspect is performed.

In a possible implementation, the memory is located outside the communication device. In another possible implementation, the memory is located inside the communication device. In this embodiment of the application, the processor and memory may alternatively be integrated into one component. In other words, the processor and memory may alternatively be integrated together.

In a possible design, the communication device further includes one or more communication interfaces. The one or more communication interfaces are coupled to the one or more processors, and the one or more communication interfaces are configured to communicate with another module other than the communication device. For the communication interfaces, the one or more communication interfaces are coupled to the one or more processors.

According to a fourteenth aspect, a communication device is provided. The communication device includes an interface circuit and a logic circuit. The interface circuit is coupled to the logic circuit. The logic circuit is configured to perform a communication method according to the first aspect or any one of the possible designs of the first aspect, or to perform a communication method according to the fourth aspect or any one of the possible designs of the fourth aspect, or to perform a communication method according to the seventh aspect or any one of the possible designs of the seventh aspect, or to perform a communication method according to the tenth aspect or any one of the possible designs of the tenth aspect, and the interface circuit is configured to communicate with another module other than the communication device.

According to a fifteenth aspect, a computer readable storage medium is provided. The computer readable storage medium stores computer instructions or programs. When the computer instructions or programs are executed or run on a computer, the computer performs a communication method according to the first aspect or any one of the possible designs of the first aspect, or performs a communication method according to the fourth aspect or any one of the possible designs of the fourth aspect, or performs a communication method according to the seventh aspect or any one of the possible designs of the seventh aspect, or performs a communication method according to the tenth aspect or any one of the possible designs of the tenth aspect.

According to a sixteenth aspect, a computer program product is provided that includes computer instructions. When the computer program product runs on a computer, a communication method according to the first aspect or any one of the possible designs of the first aspect is performed, or a communication method according to the fourth aspect or any one of the possible designs of the fourth aspect is performed, or a communication method according to the seventh aspect or any one of the possible designs of the seventh aspect is performed, or a communication method according to the tenth aspect or any one of the possible designs of the tenth aspect is performed.

According to a seventeenth aspect, an embodiment of the present application provides a computer program. When the computer program runs on a computer, a communication method according to the first aspect or any one of the possible designs of the first aspect, or a communication method according to the fourth aspect or any one of the possible designs of the fourth aspect, or a communication method according to the seventh aspect or any one of the possible designs of the seventh aspect is performed.

For the technical effects provided by any of the designs in the thirteenth to seventeenth aspects, please refer to the technical effects provided by any of the possible designs in the first aspect, the technical effects provided by any of the possible designs in the fourth aspect, the technical effects provided by any of the possible designs in the seventh aspect, or the technical effects provided by any of the possible designs in the tenth aspect. Details will not be described again.

According to an 18th aspect, a communication system is provided. The communication system includes a first AP according to any of the second and third aspects and a first STA according to any of the fifth and sixth aspects, or includes a first AP according to any of the eighth and ninth aspects and a first STA according to any of the eleventh and twelfth aspects.

2 is a schematic diagram of a frame format of a multi-BSSID element according to an embodiment of the present application; 2 is a schematic diagram of a frame format of a Reduced Neighbor Report element according to an embodiment of the present application; 1 is a schematic diagram of a frame format of a TBTT information field according to an embodiment of the present application. 1 is a schematic diagram of the structure of a communication system according to an embodiment of the present application; 1 is a schematic diagram of the structure of a communication system according to an embodiment of the present application; 1 is a schematic diagram of the structure of a communication system according to an embodiment of the present application; 1 is a schematic diagram of a structure of a communication device according to an embodiment of this application; 1 is a flowchart of a communication method according to an embodiment of the present application. FIG. 2 is a schematic diagram of a frame format of a multilink element according to an embodiment of the present application; FIG. 2 is a schematic diagram of a frame format of elements related to channel switching according to an embodiment of the present application; FIG. 2 is a time sequence diagram of a signal according to an embodiment of the present application. FIG. 2 is a schematic diagram of a structure of a multi-link device according to an embodiment of the present application. 1 is a flowchart of a communication method according to an embodiment of the present application. 2 is a schematic diagram of a frame format of an ML element according to an embodiment of the present application. FIG. 2 is a diagram of a signal time sequence according to an embodiment of the present application. 1 is a schematic diagram of a structure of a first AP according to an embodiment of this application; 2 is a schematic diagram of a structure of a first STA according to an embodiment of this application;

Before describing the embodiments of this application, the technical terms used in the embodiments of this application are described.

To greatly increase the service transmission rate of wireless local area network (WLAN) systems, the Institute of Electrical and Electronics Engineers (IEEE) 802.11ax standard further uses orthogonal frequency division multiple access (OFDMA) technology based on the existing orthogonal frequency division multiplexing (OFDM) technology. OFDMA technology can support multiple nodes to transmit and receive data simultaneously, which achieves multi-station diversity gain. In addition, the Federal Communications Commission (FCC) has opened up a new free frequency band from 5925MHz to 7125MHz, which is hereinafter referred to as 6GHz. Thus, the operating range of 802.11ax-compliant devices is extended from 2.4GHz and 5GHz to 2.4GHz, 5GHz, 6GHz, and the like.

IEEE 802.11ax next-generation Wi-Fi protocol extremely high throughput (EHT) devices are forward compatible. Therefore, the devices also support the operating spectrum of 802.11ax compliant devices, i.e., 2.4 GHz, 5 GHz, and 6 GHz frequency bands. IEEE 802.11ax next-generation wireless fidelity (WiFi) protocol EHT devices perform channel division based on the latest open and free 6 GHz frequency band and can support bandwidths larger than the maximum bandwidth of 160 MHz supported in 5 GHz, which can support, for example, 320 MHz.

The peak throughput for IEEE 802.11ax next generation Wi-Fi EHT devices can be increased by using ultra-wide bandwidth and also by increasing the number of streams, e.g., increasing the number of streams to 16, through cooperation in multiple frequency bands (2.4 GHz, 5 GHz, and 6 GHz) and the like. In the same frequency band, the peak throughput can be further increased through cooperation or otherwise in multiple channels, which reduces the service transmission delay. In this specification, multiple frequency bands or multiple channels are collectively referred to as multiple links.

IEEE 802.11ax next-generation Wi-Fi EHT devices use multi-link cooperation technology to aggregate multiple non-contiguous links to form ultra-wide bandwidth. In addition to aggregating higher bandwidth, multi-link cooperation technology can further be used to simultaneously transmit data packets of the same service to the same station.

A multiple basic service set identifier set (which may be called a multi-BSSID set) can be understood as a set of several cooperating access points (APs). All cooperating APs use the same operating class, the same channel number, and the same antenna interface. In a multi-BSSID set, there is only one Transmitted BSSID AP, and the other APs are Nontransmitted BSSID APs. Information about the multi-BSSID set (i.e., the Multi-BSSID element) is carried in a beacon frame, a probe response frame, or a neighbor report sent by the Transmitted BSSID AP. Information about the BSSID of the nontransmitted BSSID AP is derived by the station based on the beacon frame, the probe response frame, the Multi-BSSID element, or the like. The BSSID of the nontransmitted BSSID AP is calculated based on the BSSID of the Transmitted BSSID AP and the BSSID index field in the Multi-BSSID index element in the Nontransmitted BSSID profile subelement corresponding to the nontransmitted BSSID. For specific methods, please refer to the 802.11-2020 protocol.

A multi-BSSID set can also be understood as including multiple APs. Each AP manages one BSS, and different APs may have different SSIDs and permissions, e.g., security mechanisms or transmission opportunities.

In a multi-BSSID set, only APs whose BSSID is a broadcasted BSSID can send beacon frames and probe response frames, and APs whose BSSID is not a broadcasted BSSID do not send beacon frames. Therefore, if a probe request frame sent by a STA is sent to an AP whose BSSID is an unbroadcasted BSSID in a multi-BSSID set, the AP whose BSSID is a broadcasted BSSID in the multi-BSSID set will help to respond and send a probe response frame.

Among the multiple APs in a multi-BSSID set, the BSSID of one AP is set to the transmitted BSSID, and the transmitted BSSID AP may be referred to as the transmitted AP. The BSSID of another AP is set to the untransmitted BSSID, and the untransmitted BSSID AP may be referred to as the untransmitted AP.

The beacon frame transmitted by the transmitting AP may include a multi-BSSID element. The frame format of the multi-BSSID element is depicted in FIG. 1. The multi-BSSID element may include an element ID field, a length field, a maximum BSSID indicator field, and an optional subelement field. The maximum BSSID indicator field indicates the maximum number n of BSSIDs included in the multi-BSSID set. The optional subelement field includes information about the BSSIDs of the non-transmitted BSSID AP, specifically the non-transmitted BSSID profile subelement.

In a communication scenario where various types of users are supported within a small area, if different independent APs are used within the small area, each independent AP tries to find a free channel. In this case, channel interference between independent APs cannot be avoided. Channel interference can be avoided by using a scheme where one AP supports multiple BSSIDs, i.e., one AP is virtualized into multiple APs for different service types or user types.

To associate with an AP and establish a connection to it, a station must first discover the AP through scanning. There are two types of scanning: active scanning and passive scanning.

Passive scanning is a method of discovering APs by listening to management frames transmitted by APs on a channel. The management frames can be beacon frames, association response frames, reassociation response frames, authentication frames, probe response frames, or the like.

For example, a station may move to a different channel to look for a reduced neighbor report element in a beacon frame transmitted by an AP. Once the station obtains basic information about the AP's neighbor APs based on the beacon frame, the station may further obtain other additional information from the AP by exchanging probe request frames and probe response frames. Of course, a station may move to a different channel to look for a beacon frame transmitted by an AP and know all the information of the AP directly.

In active scanning mode, a station actively sends a broadcast probe request when it does not detect a beacon frame. After receiving the probe request frame, the AP replies with a probe response frame if certain conditions are met.

In the scanning process, to help stations in fast scanning, the AP carries a reduced neighbor report element (RNR) in management frames, such as beacon frames or probe response frames, to prevent stations from making continuous channel scans. This reduces the scanning time of the station.

Reduced Neighbor Report Element: An AP may carry a reduced neighbor report element in a management frame. During scanning, a station may receive a management frame transmitted by an AP, obtain information about neighboring APs based on the reduced neighbor report element in the management frame, and then choose an appropriate AP to associate with.

Specifically, the reduced neighbor report element generally carries one or more neighbor AP information fields to describe information about one or more neighbor APs and the respective BSSs belonging to each of the neighbor APs. As depicted in FIG. 2, the reduced neighbor report element may include the following fields: a target beacon transmission time information header (TBTT information header) field, an operating class field, a channel number field, and a TBTT information set field.

The target transmission time information header field in the beacon frame may include a TBTT information field type field, a filtered neighbor AP field, a reserved field, a TBTT information count field, and a TBTT information length field.

The TBTT information field type field may indicate the TBTT information type and is used together with the TBTT information length field to indicate the format of the TBTT information field. The Filtered AP field may indicate whether the SSID of any BSS carried in the Neighbor AP Information field matches the SSID in the probe response frame. The number of bits in the reserved field may be 1. The TBTT information count field may indicate the number of TBTT information fields included in the TBTT information set. The TBTT information length field may indicate the length of each TBTT information field. The specific information formats carried in different lengths may be represented in Table 1 below.

As shown in FIG. 3, when the TBTT information length is 12 bytes, the TBTT information field may include a neighbor AP target beacon transmission time offset (neighbor AP TBTT offset) field indicating the time offset between the transmission of a beacon frame by the neighbor AP and the transmission of a beacon frame by the reporting AP, a BSSID field indicating the BSS identifier corresponding to the neighbor AP, a Short Service Set Identifier (Short SSID) field indicating the identifier of the service set to which the neighbor AP belongs, a BSS parameter field indicating related parameters of the neighbor AP, a 20MHz power spectral density (PSD) field indicating the maximum transmission power of the reported AP in the primary 20MHz, and a multi-link device (MLD) parameter field.

The BSS parameters field includes an on channel tunnel recommended (OCT recommended) field, which indicates that the neighboring AP is expected to exchange management type media access control protocol data units (MPDUs) with the reporting AP by using the OCT mechanism; a Same SSID field, which indicates whether the neighboring AP and the reporting AP have the same SSID; a multi-basic service set identifier field, which indicates whether the neighboring AP belongs to a part of a multi-BSSID set; and if the neighboring AP belongs to a part of a multi-BSSID set, a transmitted basic service set identifier field, which further indicates whether the neighboring AP has a transmitted or untransmitted BSSID; a member of ESS with 2.4/5GHz Co-located AP field, which indicates whether the neighboring AP shares a location with a 2.4/5GHz AP (in other words, whether the neighboring AP is a 6GHz-only AP) and whether the neighboring AP is a member of an extended service set; and an unsolicited probe response enabled field, which indicates whether the neighboring AP enables unsolicited probe responses. It may include an active field and a Co-located AP field that indicates whether the neighbor AP and the reporting AP are in the same location.

The MLD parameters field may include an MLD identifier (ID) field indicating the identifier of the AP MLD to which the reported AP belongs, a link ID indicating the link identifier of the reported AP, where the link ID represents the combination <operation class, channel number, BSSID of the AP>, and a BSS parameter change count field indicating the change count of important BSS parameters of the reported AP, with an initial value of 0.

It should be noted that in the embodiments of this application, the AP described in the neighbor report element or reduced neighbor report element is the reported access point, and the neighbor AP subsequently mentioned can be understood as the reported AP. The AP that transmits the neighbor report element or reduced neighbor report element is the reporting access point.

In a WLAN communication system, a multi-link device capable of supporting simultaneous communication on multiple links is provided to improve transmission efficiency. A multi-link device may include one or more stations. A station may be an AP or a non-access point station (non-AP STA). A non-AP STA may also be simply referred to as an STA.

When a STA associated with an AP in an AP multilink device is in a dormant state, the STA belongs to a non-AP multilink device, and the AP is performing a channel switch (in this case, the beacon frame transmitted by the AP on the link on which the AP operates carries elements related to the channel switch, and if the AP is an untransmitted BSSID AP in the multi-BSSID set, the beacon frame transmitted by the transmitted AP corresponding to the AP carries elements related to the channel switch of the AP), another AP from the same AP multilink device (if the AP is an untransmitted BSSID AP in the multi-BSSID set, the other AP is a transmitted AP in the multi-BSSID set) may carry elements related to the channel switch of the AP in its management frame. STAs associated with another AP (belonging to the same non-AP multilink device) know that the AP is performing a channel switch. Thus, STAs belonging to the same non-AP multilink device know this information.

However, if that AP performs a channel switch before another AP belonging to the same AP multilink device transmits a management frame, that other AP (sometimes referred to as the reporting AP) does not carry any information about the channel switch of that AP. In other words, non-AP multilink devices cannot know that the AP has performed a channel switch.

To solve this problem, an embodiment of this application provides a communication method and apparatus. A first AP generates a management frame, the management frame includes a capability information field, the capability information field includes first indication information, the first indication information indicates whether another AP in the first AP multilink device has performed channel switching, the first AP multilink device includes a first AP, and the first AP transmits the management frame to a first station STA.

In this embodiment of the application, when sending a management frame, the first AP may carry the first indication information to indicate whether another AP in the first AP multi-link device has performed a channel switch. In this way, the first STA associated with the first AP and belonging to the non-AP MLD determines whether another AP in the first AP multi-link device has performed a channel switch based on the first indication information. If another AP in the first AP multi-link device has performed a channel switch, the STA obtains the channel switch information of the AP that performed the channel switch. Thus, the STA that belongs to the same non-AP MLD and is associated with the AP that performed the channel switch (even if the STA is in a dormant state) knows that the AP associated with the STA has performed a channel switch, and knows about the channel switch information after the channel switch.

The following describes in detail the implementation of the embodiments of this application with reference to the accompanying drawings of this specification.

The wireless communication system applicable to the embodiments of this application may be a WLAN or a cellular network. The communication method may be implemented by a communication device in the wireless communication system, or a chip or processor in the communication device. The communication device may be a wireless communication device that supports simultaneous transmission performed on multiple links. For example, the communication device is called a multi-link device or a multi-band device. Compared with a device that supports only single-link transmission, the multi-link device has higher transmission efficiency and higher throughput.

A multi-link device may include one or more affiliated stations (STAs). An affiliated station is a logical station and may operate in one link. An affiliated station may be an AP or a STA. For ease of description, in this application, a multi-link device whose affiliated station is an AP may be referred to as a multi-link AP, a multi-link AP device, or an AP multi-link device (AP MLD). A multi-link device whose affiliated station is a non-AP STA may be referred to as a multi-link STA, a multi-link STA device, or an STA multi-link device (STA MLD). For ease of description, "a multi-link device includes an affiliated STA" is also simply described as "a multi-link device includes a STA" in the embodiments of this application.

A multilink device may contain multiple logical stations, each operating on one link, although it should be noted that multiple logical stations are permitted to operate on the same link.

The multilink device may implement wireless communication in accordance with the 802.11 series protocol, for example, in accordance with an EHT station or in accordance with a station based on or compatible with 802.11be, to implement communication with another device. Of course, the other device may or may not be a multilink device.

For example, the multilink device in the embodiment of this application may be a single antenna device or may be a multi-antenna device. For example, the multilink device may be a device having more than two antennas. The number of antennas included in the multilink device is not limited in this embodiment of this application. In the embodiment of this application, the multilink device may allow services of the same access type to be transmitted on different links, or even allow the same data packets to be transmitted on different links. Alternatively, the multilink device may not allow services of the same access type to be transmitted on different links, but may allow services of different access types to be transmitted on different links.

For example, a multi-link device is a device having wireless communication capabilities. The device may be a system-wide device, or a chip, processing system, or the like mounted on the system-wide device. The device on which the chip or processing system is mounted may be controlled by the chip or processing system to implement the methods and functions in the embodiments of this application. For example, the STA MLD in the embodiments of this application may have wireless transceiver capabilities and support 802.11 series protocols, and may communicate with an AP MLD, another STA MLD, or a single-link device. For example, the STA MLD is any user communication device that allows a user to communicate with an AP and further communicate with a WLAN. For example, the STA MLD may be a user equipment that can be connected to a network, such as a tablet computer, a desktop computer, a laptop computer, a notebook computer, an ultra-mobile personal computer (UMPC), a handheld computer, a netbook, a personal digital assistant (PDA), or a mobile phone, or may be an Internet of Things node in the Internet of Things, or may be an in-vehicle communication device in the Internet of Vehicles. The STA MLD may alternatively be a chip and processing system in the aforementioned terminal.

The AP MLD in the embodiment of this application is a device that serves the STA MLD and may support the 802.11 series protocol. For example, the AP MLD may be a communication entity such as a communication server, a router, a switch, or a bridge, or the AP MLD may include various types of macro base stations, micro base stations, and relay stations. Of course, the AP MLD may alternatively be chips and processing systems in various types of devices to realize the methods and functions in the embodiments of this application. In addition, the multilink device may support high-rate and low-latency transmission. With the continuous evolution of application scenarios of wireless local area networks, the multi-link device can be further applied to more scenarios, for example, sensor nodes in smart cities (e.g., smart water meters, smart power meters, and smart air detection nodes), smart devices in smart homes (e.g., smart cameras, projectors, display screens, televisions, stereos, refrigerators, and washing machines), nodes in the Internet of Things, entertainment terminals (e.g., wearable devices such as AR and VR), smart devices in smart offices (e.g., printers or projectors), Internet of Vehicles devices in the Internet of Vehicles, and some infrastructures in daily life scenarios (e.g., vending machines, self-service navigation consoles in supermarkets, self-service cash registers, and self-service ordering machines). The specific formats of the STA MLD and AP MLD are not specifically limited in the embodiments of this application, and are merely examples for the description herein. The 802.11 protocol can be a protocol that supports 802.11be or is compatible with 802.11be.

The operating frequency bands of the multi-link device may include one or more of below 1 GHz, 2.4 GHz, 5 GHz, 6 GHz, and high frequency 60 GHz, and may include, for example, 2.4 GHz, 5 GHz, and 6 GHz.

In a multi-link device, each link may include a link identifier, and a link identifier represents one station operating on a link. In other words, if there is more than one station on a link, then more than one link identifier represents the station. Links referred to below sometimes also represent stations operating on the link.

During data transmission, the AP MLD and the STA MLD may use the link identifier to identify the link or the station on the link. Before communication, the AP MLD and the STA MLD may first negotiate or communicate with each other about the association between the link identifier and the link or the station on the link. Then, during data transmission, the link identifier is carried to indicate the link or the station on the link, so that the transmission of a large amount of signaling information is not used to indicate the link or the station on the link. This reduces the signaling overhead and improves the transmission efficiency.

In an example, a management frame, e.g., a beacon frame, transmitted by an MLD AP to establish a BSS carries one element, which includes multiple link identifier information fields. The link identifier information field may indicate a correspondence between a link identifier and a station operating in a link corresponding to the link identifier. The link identifier information field not only includes a link identifier, but also includes one or more of the following information: a MAC address, an operating class, and a channel number. One or more of the MAC address, the operating class, and the channel number may indicate a link. For an AP, the MAC address of the AP is the BSSID of the AP. In another example, in a multilink device association process, the AP MLD and the STA multilink device negotiate multiple link identifier information fields. A multilink device association means that an AP in the AP MLD associates with a STA in the STA MLD once. This association may help multiple STAs in the STA MLD to associate with multiple APs in the AP MLD, with one STA associating with one AP.

In subsequent communications, the AP MLD or STA multilink device identifies or represents the station in the STA multilink device by using a link identifier. The link identifier may further represent one or more attributes of the station's MAC address, operation class, and channel number. The MAC address may alternatively be the association identifier of the AP MLD after association. Optionally, if multiple stations operate on one link, the meaning identified by the link identifier (which is a numeric ID) includes not only the operation class including the link and channel number, but also the identifier of the station operating on the link, for example, the station's MAC address or association identifier (AID).

By way of example, the embodiments of this application are primarily described using networks in which IEEE 802.11 is deployed, but those skilled in the art will readily appreciate that various aspects of this application can be extended to other networks using various standards or protocols, such as BLUETOOTH (registered trademark), high performance radio LAN (HIPERLAN) (a wireless standard similar to the IEEE 802.11 standard and used primarily in Europe), wide area networks (WANs), wireless local area networks (WLANs), personal area networks (PANs), or other known or later developed networks. Thus, various aspects provided in this application may be applicable to any suitable wireless network, regardless of the coverage area and wireless access protocol used.

In FIG. 4, a wireless local area network is used as an example to describe a communication system 400 to which an embodiment of this application is applied. The communication system 400 includes a station 401 and a station 402. The station 401 may communicate with the station 402 through multiple links to improve throughput. The station 401 may be a multi-link device, and the station 402 may be a single-link device, a multi-link device, or the like. In a scenario, the station 401 is an AP MLD and the station 402 is a STA MLD or station (e.g., a single-link station). In another scenario, the station 401 is a STA MLD and the station 402 is an AP (e.g., a single-link AP) or an AP MLD. In yet another scenario, the station 401 is an AP MLD and the station 402 is an AP MLD or an AP. In yet another scenario, the station 401 is a STA MLD and the station 402 is a STA MLD or STA (e.g., a single-link station). Of course, the wireless local area network may further include other devices. The quantities and types of devices depicted in Figure 4 are merely examples.

5 and 6 respectively show schematic diagrams of the structure of communication system 500 and communication system 600. In communication system 500 and communication system 600, for example, a multi-link device in a wireless local area network communicates with another device through multiple links.

Figure 5 shows a scenario in which an AP MLD communicates with a STA MLD. The AP MLD includes associated AP1 and associated AP2. The STA MLD includes associated STA1 and associated STA2. The AP MLD and the STA MLD perform simultaneous communication on link 1 and link 2.

Figure 6 is a scenario in which AP MLD601 communicates with STA MLD602, STA MLD603, and STA604. AP MLD601 includes affiliated AP601-1 to affiliated AP601-3. STA MLD602 includes three affiliated STAs, namely STA602-1, STA602-2, and STA602-3. STA MLD603 includes two affiliated STAs, namely STA603-1 and STA603-2. STA604-1 and STA604 are single-link devices. AP MLD601 may communicate with STA MLD602 using link 1, link 2, and link 3 separately, communicate with STA MLD603 using link 2 and link 3, and communicate with STA604 using link 1. In the example, STA604 operates in the 2.4 GHz frequency band. In the STA MLD 603, the STA 603-1 operates in the 5 GHz frequency band, and the STA 603-2 operates in the 6 GHz frequency band. In the STA MLD 602, the STA 602-1 operates in the 2.4 GHz frequency band, the STA 602-2 operates in the 5 GHz frequency band, and the STA 602-3 operates in the 6 GHz frequency band. The AP 601-1 operating in the 2.4 GHz frequency band in the AP MLD 601 may perform uplink or downlink data transmission with the STA 604 and the STA 602-2 in the STA MLD 602 on link 1. The AP 601-2 operating in the 5 GHz frequency band in the AP MLD 601 may perform uplink or downlink data transmission with the STA 603-1 operating in the 5 GHz frequency band in the STA MLD 603 on link 2, and may further perform uplink or downlink data transmission with the STA 602-2 operating in the 5 GHz frequency band in the STA MLD 602 on link 2. AP601-3 operating in the 6 GHz frequency band in AP MLD601 may perform uplink or downlink data transmission with STA602-3 operating in the 6 GHz frequency band in STA MLD602 on link 3, and may further perform uplink or downlink data transmission with STA603-2 in the STA MLD on link 3.

It should be noted that FIG. 5 shows that AP MLD supports only two frequency bands. FIG. 6 shows an example in which AP MLD 701 supports only three frequency bands (2.4 GHz, 5 GHz, and 6 GHz), where each frequency band corresponds to one link, and AP MLD 701 may operate in one or more links among link 1, link 2, or link 3. On the AP side or STA side, the link here may also be understood as a station operating in a link. In practical applications, AP MLD and STA MLD may further support more or fewer frequency bands. In other words, AP MLD and STA MLD may operate in more or fewer links. This is not limited in the embodiments of this application.

During the specific implementation as shown in FIG. 4 to FIG. 6, each access point device and each station device may use the composition structure or include the components shown in FIG. 7. FIG. 7 is a schematic composition diagram of a communication device 700 according to an embodiment of this application. The communication device 700 may be an access point device or a chip or system-on-chip in an access point device, or may be a station device or a chip or system-on-chip in a station device. As shown in FIG. 7, the communication device 700 includes a processor 701, a transceiver 702, and a communication line 703.

Further, the communication device 700 may further include a memory 704. The processor 701, the memory 704, and the transceiver 702 may be connected via a communication line 703.

The processor 701 may be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processing (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. Alternatively, the processor 701 may be another device having processing capabilities, such as a circuit, a component, or a software module. This is not limiting.

The transceiver 702 is configured to communicate with another device or another communication network. The other communication network may be an Ethernet, a radio access network (RAN), a wireless local area network (WLAN), or the like. The transceiver 702 may be a module, a circuit, a transceiver, or any device capable of achieving communication.

The communication line 703 is configured to transmit information between components included in the communication device 700.

The memory 704 is configured to store instructions. The instructions may be a computer program.

The memory 704 may be a read-only memory (ROM) or another type of static storage device capable of storing static information and/or instructions, a random access memory (RAM) or another type of dynamic storage device capable of storing information and/or instructions, or may be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or another type of compact disc storage, an optical disc storage (including a compact optical disc, a laser disc, an optical disc, a digital versatile disc, a Blu-ray disc, or the like), a magnetic disc storage medium or another magnetic storage device, or the like. This is not limited to this.

It should be noted that the memory 704 may be independent of the processor 701 or may be integrated with the processor 701. The memory 704 may be configured to store instructions, program codes, data, or the like. The memory 704 may be located inside the communication device 700 or outside the communication device 700. This is not limited. The processor 701 is configured to execute instructions stored in the memory 704 to realize the communication methods provided in the following embodiments of this application.

In an example, the processor 701 may include one or more CPUs, e.g., CPU0 and CPU1 in FIG. 7.

In an optional implementation, the communication device 700 may include multiple processors. For example, in addition to the processor 701 in FIG. 7, the communication device 700 may further include a processor 707.

In an optional implementation, the communication device 700 further includes an output device 705 and an input device 706. For example, the input device 706 is a device such as a keyboard, a mouse, a microphone, or a joystick, and the output device 705 is a device such as a display or a speaker.

It should be noted that the communication device 700 may be a desktop computer, a portable computer, a network server, a mobile phone, a tablet computer, a wireless terminal, an embedded device, a chip system, or a device having a structure similar to that in FIG. 7. In addition, the compositional structure depicted in FIG. 7 does not constitute a limitation on the communication device. In addition to the components depicted in FIG. 7, the communication device may include more or fewer components than those depicted in the figure, or some components may be combined, or a different component arrangement may be used.

In embodiments of this application, the chip system may include a chip, or may include a chip and other separate components.

In addition, in the embodiments of this application, cross-references to operations, terms, and the like may be made. This is not limiting. In the embodiments of this application, names of messages exchanged between devices, names of parameters in messages, or the like are merely examples. Alternatively, during a particular implementation, other names may be used. This is not limiting.

With reference to any communication system in FIG. 4 to FIG. 6, the following describes a communication method provided in an embodiment of this application with reference to FIG. 8. The first AP may be any reporting AP in the communication system represented in FIG. 4 to FIG. 6 (a reporting AP is an AP that transmits management frames such as beacon frames and probe response frames), and the first STA may be any STA associated with the first AP in the communication system represented in FIG. 4 to FIG. 7, belonging to a STA multi-link device (or may be described as a non-AP MLD). The first AP multi-link device in which the first AP is located and the STA multi-link device in which the first STA is located may be connected through multi-link communication. Both the first AP and the first STA described in the following embodiment may have the components represented in FIG. 7.

FIG. 8 is a flowchart of a communication method according to an embodiment of the present application. As depicted in FIG. 8, the method may include the following steps:

Step 801: The first access point AP generates a management frame.

The first AP multilink device may include at least one AP, and the at least one AP may include the first AP. The management frame may include a capability information field, and the capability information field may include the first indication information.

For example, the management frame may be one or more of the following: a beacon frame, an association response frame, a reassociation response frame, an authentication frame, and a probe response frame.

The first indication information may indicate whether another AP in the first AP multilink device has performed a channel switch, or the first indication information may indicate whether an AP in the first AP multilink device, including the first AP, has performed a channel switch.

The following uses an example in which the first indication information indicates whether another AP in the first AP multilink device has performed channel switching. It can be understood that the following embodiment is also applicable to the case in which the first indication information indicates whether an AP, including the first AP, in the first AP multilink device has performed channel switching.

For example, when another AP in the first AP multilink device performs a channel switch, the first indication information may be set to a first value, e.g., 1. Otherwise, the first indication information is set to a second value, e.g., 0. It should be noted that if the first indication information is set to a first value, the value needs to be maintained until the next delivery traffic indication map (DTIM) signal frame. After the DTIM beacon frame, the first indication information is reset to the second value.

Optionally, the capability information field further includes a first critical update flag signaling.

The first critical update flag signaling may indicate whether a critical parameter update value of an AP in the first AP multilink device changes. The critical parameter update value may also be referred to as a BSS parameter change count value or as a value of the BSS parameter change count field.

For example, when any event among the critical basic service set BSS parameter events corresponding to one AP in the first AP multilink device occurs, the first AP adjusts the value of the AP's critical parameter update value. When the critical parameter update value of one AP in the first AP multilink device changes, the first AP adjusts the first critical update flag signaling.

For example, each time a critical BSS parameter event occurs for any AP, the AP's critical parameter update value is incremented by 1.

In another example, when the value of the critical parameter update value of one AP in the first AP multilink device changes, the first critical update flag signaling may be set to a first value, e.g., 1, otherwise, the first critical update flag signaling is set to a second value, e.g., 0. It should be noted that if the first critical update flag signaling is set to the first value, the value needs to be maintained until the next DTIM beacon frame. After the DTIM beacon frame, the first critical update flag signaling is reset to the second value.

As shown in Figure 3, the critical parameter update value is located in the BSS Parameter Change Count field in the MLD parameters field in the RNR element.

The significant BSS parameter events are the following events: modification of the enhanced distributed channel access parameters element, modification of the direct sequence spread spectrum parameter set, modification of the high throughput operation element, inclusion of a wide bandwidth channel switch element , inclusion of a channel switch wrapper element, inclusion of an operating mode notification element, modification of the very high throughput operation element, modification of the high efficient operation element, insertion of a broadcast target wakeup time element, inclusion of the BSS color change announcement element, modification of the MU enhanced distributed channel access parameter set element, inclusion of a The method may include at least one of modifying the spatial reuse parameter set element, modifying the spatial reuse parameter set element, and modifying the very high throughput EHT operation element.

Furthermore, the important BSS parameter event may include any one of the events described above.

Optionally, the critical BSS parameter event further includes a modification of the contention free parameter set element.

For example, the first AP may carry the critical parameter update values of all APs other than the first AP in the first AP multilink device in the MLD parameters field in the RNR element of the management frame shown in FIG. 3. The first AP may further carry the critical parameter update values of the first AP in the common information field in the multilink element shown in FIG. 9.

It should be noted that the critical BSS parameter event does not include any one of the following events: inclusion of channel switch announcement element, inclusion of extended channel switch announcement element, inclusion of quiet element, and inclusion of quiet channel element.

For a first AP multilink device, the value of the critical parameter update value of another AP does not change regardless of whether the management frame transmitted by the other AP includes an element related to channel switching. In other words, the value of the first critical update flag signaling does not change regardless of whether the management frame transmitted by the other AP includes an element related to channel switching.

Whether the management frame transmitted by another AP includes an element related to channel switching can also be described as whether the other AP is performing a channel switch. In other words, whether the other AP is performing a channel switch does not cause the value of the critical parameter update value of the other AP to change, i.e., whether the other AP is performing a channel switch does not cause the value of the first critical update flag signaling to change.

Compared with the 802.11ax standard and the 802.11-2020 protocol, the events related to the inclusion of a channel switch announcement element, the events related to the inclusion of an extended channel switch announcement element, the events related to the inclusion of a quiet element, and the events related to the inclusion of a quiet channel element are removed from the important BSS parameter events. In this way, the STA multilink device associated with the first AP multilink device does not obtain the AP's repeated channel switch information based on the RNR element and the multilink element in the management frame. This reduces the power consumption of the STA multilink device and saves air interface transmission opportunities.

In a possible design, when another AP in the first AP multilink device is performing channel switching (i.e., another AP transmits a beacon frame or a probe response frame carrying an element related to channel switching), the multilink element in the management frame transmitted by the first AP may carry the element related to channel switching of the other AP, so that the first STA obtains the element related to channel switching of the AP performing channel switching based on the management frame. In this way, a STA belonging to the same STA multilink device as the first STA and associated with the AP performing channel switching obtains the element related to channel switching of the AP associated with the STA.

The channel switch related elements may include one or more of the following: a channel switch announcement element, an extended channel switch announcement element, and a maximum channel switch time element.

As shown in FIG. 10(a), the channel switch notification element may include an element number field, a length field, a channel switch mode field, a new channel number field, and a channel switch count field. As shown in FIG. 10(b), the extended channel switch notification element may include an element number field, a length field, a channel switch mode field, a new operating class field, a new channel number field, and a channel switch count field.

The channel switch count field indicates the number of TBTTs before the station transmitting the channel switch element or extended channel switch element switches to a new channel, or to a new operating class and new channel. For example, setting the channel switch count field to 1 may indicate that the switch will occur immediately before the next TBTT, and setting the channel switch count field to 0 may indicate that the switch will occur any time after the frame is transmitted. The new channel number field indicates the channel number after the channel switch, and the new operating class field indicates the operating class after the channel switch.

It should be noted that the time fields in each element related to channel switching may use as a reference the beacon transmission time and beacon interval of the AP performing the channel switch.

In yet another possible design, before the channel switching target time, the RNR element in the management frame transmitted by the first AP includes channel information of the AP that performed the channel switching (reported neighboring AP), where the channel information includes the AP's working operating class and channel number before the time (i.e., the operating class and channel number before the channel switching). After the channel switching target time, the RNR element in the management frame transmitted by the first AP includes channel information of the AP that performed the channel switching (reported neighboring AP), where the channel information includes the AP's working operating class and channel number after the time (i.e., the operating class and channel number after the channel switching).

It should be noted that the operating class and channel number in the above channel information can alternatively be the channel number.

Step 802: The first AP transmits a management frame to the first STA. In response, the first STA receives the management frame.

Step 803: When the first indication information indicates that another AP in the first AP multilink device has performed a channel switch, the first STA receives channel switch information of the AP that performed the channel switch, so that a STA that belongs to the same STA multilink device as the first STA and is associated with the AP that performed the channel switch obtains the channel switch information.

The first STA may be a STA associated with the first AP in the STA multilink device.

For example, STAs other than the first STA in the STA multilink device are in a dormant state, and the first STA listens to the operational link. The first STA may determine whether another AP in the first AP multilink device has performed a channel switch based on the first indication information in the management frame transmitted by the first AP.

In a possible design, after the first STA receives a management frame transmitted by the first AP, if another AP in the first AP multilink device is performing a channel switch, the first STA may analyze the multilink element in the management frame to obtain an element related to channel switching of the AP performing the channel switch. If none of the APs in the first AP multilink device is performing a channel switch (e.g., a channel switch has occurred), the multilink element in the management frame received by the first STA does not carry an element related to channel switching.

In yet another possible design, after the first STA receives the management frame transmitted by the first AP, if the first indication information indicates that another AP in the first AP multilink device has performed a channel switch, the first STA may analyze the RNR element in the management frame to obtain channel information of the AP that performed the channel switch. If the first indication information indicates that no other AP in the first AP multilink device has performed a channel switch, the first STA may analyze the RNR element in the management frame, since the RNR element is used to discover neighboring APs, or may not analyze the RNR element in the management frame to reduce power consumption. Optionally, the STA multilink device is associated with the first AP multilink device.

When the first indication information indicates that an AP in the first AP multilink device has performed a channel switch (which may alternatively be understood as the channel information of any other APs in the RNR element related to the first AP multilink device has changed, or the channel information of the first AP has changed) or that another AP has performed a channel switch (which may alternatively be understood as the channel information of any other APs in the RNR element related to the first AP multilink device has changed), the first STA may analyze the RNR element in the management frame to obtain the channel information of the AP that performed the channel switch. In addition, another STA belonging to the same STA multilink device as the first STA also knows the channel information, e.g., the STA associated with the AP that performed the channel switch, to facilitate subsequent communication with the AP associated with the STA based on the channel switch information.

For example, as shown in FIG. 11, a STA multilink device includes STA1 and STA2, and establishes a multilink connection to a first AP multilink device, and STA1 and STA2 are associated with AP1 and AP2 in the first AP multilink device, respectively. It is assumed that STA1 is in a dormant state, and STA2 observes link 2 on which STA1 operates. When AP1 is performing channel switching, the interval between beacon frames transmitted by AP2 in link 2 is large, so that the beacon frame in link 2 does not carry a channel switching announcement element or an extended channel switching announcement element. Therefore, when the first beacon frame is transmitted in link 2, AP1 does not perform channel switching, but when the second beacon frame is transmitted in link 2, AP1 in link 1 is performing channel switching. In this case, STA2 in an awake state in the STA multilink device cannot know about the channel switching information of AP1 located in link 1. As a result, the STA multilink device cannot communicate with AP1. However, in an embodiment of this application, the first indication information is carried in a management frame, so that STA2 can determine that another AP in the first AP multilink device has performed a channel switch based on the first indication information, and further analyze the RNR element in the beacon frame to obtain the channel information of AP1, so that STA1 associated with AP1 obtains the channel information of AP1 to ensure normal communication between STA1 and AP1.

Based on the method depicted in FIG. 8, when transmitting a management frame, the first AP may carry the first indication information to indicate whether another AP in the first AP multilink device has performed a channel switch. In this way, the first STA associated with the first AP and belonging to the non-AP multilink device determines whether another AP in the first AP multilink device has performed a channel switch based on the first indication information. If another AP in the first AP multilink device has performed a channel switch, the STA obtains the channel switch information of the AP that performed the channel switch. Thus, the STA belonging to the same non-AP MLD and associated with the AP that performed the channel switch (even if the STA is in a dormant state) knows that the AP associated with the STA has performed a channel switch, and knows about the channel switch information after the channel switch.

Optionally, if the first AP is in the multi-BSSID set and the first AP is a transmitted AP, the transmitted management frame further includes an untransmitted basic service set identifier BSSID field, and the untransmitted BSSID field includes second indication information. The second indication information may indicate whether another AP in the second AP multi-link device has performed a channel switch. At least one AP in the second AP multi-link device and the first AP belong to the same multi-BSSID set. The untransmitted BSSID field is in an untransmitted BSSID capabilities element in an untransmitted BSSID profile sub-element in the multi-BSSID element. The untransmitted BSSID field may alternatively be referred to as an untransmitted BSSID capabilities field or may have another name.

The other AP in the second AP multilink device may be another AP in the second multilink device other than the transmitting AP.

For example, as shown in FIG. 12, multi-BSSID set 1 may include BSSID-1x and BSSID-1y, multi-BSSID set 2 may include BSSID-2y, BSSID-2x, and BSSID-2z, and multi-BSSID set 4 may include BSSID-4x, BSSID-4y, and BSSID-4z. For link 1, AP-1x (BSSID-1x) sending a beacon frame is used as an example. The first AP multi-link device may be AP MLD1, and the second AP multi-link device may be AP MLD3. For link 2, AP-2x (BSSID-2x) sending a beacon frame is used as an example. The first AP multi-link device may be AP MLD2, and the second AP multi-link device may be AP MLD1 and AP MLD3. For link 4, AP-4x (BSSID-4x) sending a beacon frame is used as an example. The first AP multilink device may be AP MLD2, and the second AP multilink device may be AP MLD3 and AP MLD4.

For example, when another AP in the second AP multilink device performs a channel switch, the second indication information may be set to a first value, e.g., 1. Otherwise, the second indication information is set to a second value, e.g., 0. It should be noted that if the second indication information is set to a first value, the value needs to be maintained until the next DTIM beacon frame (DTIM beacon frame with an untransmitted BSSID). After the DTIM beacon frame, the first indication information is reset to the second value.

Optionally, the untransmitted BSSID field further includes a second critical update flag signaling.

The second critical update flag signaling may indicate whether a critical parameter update value of an AP in the second AP multilink device changes.

For example, when any event among the critical BSS parameter events corresponding to one AP in the second AP multilink device occurs, the first AP adjusts the value of the AP's critical parameter update value. When the critical parameter update value of one AP in the second AP multilink device changes, the first AP adjusts the second critical update flag signaling.

For example, each time a critical BSS parameter event occurs for any AP, the AP's critical parameter update value is incremented by 1.

In another example, when the value of the critical parameter update value of any AP in the second AP multilink device changes, the second critical update flag signaling may be set to a first value, e.g., 1, otherwise, the second critical update flag signaling is set to a second value, e.g., 0. It should be noted that if the second critical update flag signaling is set to the first value, the value needs to be maintained until the next DTIM beacon frame (DTIM beacon frame with an untransmitted BSSID). After the DTIM beacon frame, the second critical update flag signaling is reset to the second value.

As shown in Figure 3, the critical parameter update value is located in the BSS Parameter Change Count field in the MLD parameters field in the RNR element.

For example, the first AP may convey, in the MLD parameters field in the RNR element of the management frame shown in FIG. 3, the critical parameter update values of other APs in the second AP multilink device other than the non-transmitting AP located in the same multi-BSSID set as the first AP. The first AP may further convey, in the common information field in the multilink element shown in FIG. 9, the critical parameter update values of the non-transmitting APs in the second AP multilink device and in the same multi-BSSID set as the first AP.

For the second AP multilink device, the value of the critical parameter update value of the other AP does not change regardless of whether the management frame transmitted by the other AP includes an element related to channel switching. In other words, the value of the first critical update flag signaling does not change regardless of whether the management frame transmitted by the other AP includes an element related to channel switching.

Whether the management frame transmitted by another AP includes an element related to channel switching can also be described as whether the other AP is performing a channel switch. In other words, whether the other AP is performing a channel switch does not cause the value of the critical parameter update value of the other AP to change, i.e., whether the other AP is performing a channel switch does not cause the value of the first critical update flag signaling to change.

Furthermore, before the channel switching target time, the RNR element in the management frame transmitted by the first AP may further include channel information of the AP in the second AP multilink device that performed the channel switching, where the channel information includes the working operation class and channel number of the AP before the time (i.e., the operating class and channel number before the channel switching). After the channel switching target time, the RNR element in the management frame transmitted by the first AP includes channel information of the AP (reported neighbor AP) in the second AP multilink device that performed the channel switching, where the channel information includes the working operation class and channel number of the AP after the time (i.e., the operating class and channel number after the channel switching).

When transmitting the management frame, the first AP may carry the second indication information to indicate whether another AP in the second AP multilink device has performed a channel switch. In this way, the first STA associated with the first AP and belonging to the non-AP MLD determines whether another AP in the second AP multilink device has performed a channel switch based on the second indication information. If another AP in the second AP multilink device has performed a channel switch, the STA obtains the channel switch information of the AP that performed the channel switch. Thus, the STA that belongs to the same non-AP MLD and is associated with the AP that performed the channel switch (even if the STA is in a dormant state) knows that the AP associated with the STA has performed a channel switch, and knows about the channel switch information after the channel switch.

Compared with the method represented in FIG. 8 to FIG. 12, in which the first indication information indicates whether another AP in the first AP multilink device has performed channel switching and the first critical update flag signaling indicates whether a critical parameter update value of an AP in the first AP multilink device has changed, the first critical update flag signaling in the embodiment of this application may be further redefined. Specifically, the first critical update flag signaling is redefined as indicating whether a critical parameter update value of an AP in the first AP multilink device has changed or whether another AP in the first AP multilink device has performed channel switching.

For example, when the critical parameter update value of an AP in the first AP multilink device changes, the first critical update flag signaling may be set to a first value, for example, 1; or when another AP in the first AP multilink device performs a channel switch, the first critical update flag signaling may be set to a first value, for example, 1; or when the critical parameter update value of an AP in the first AP multilink device changes and the channel of another AP in the first AP multilink device changes, the first critical update flag signaling may be set to a first value, for example, 1. Otherwise, the first critical update flag signaling is set to a second value, for example, 0. It should be noted that if the first critical update flag signaling is set to a first value, the value needs to be maintained until the next DTIM beacon frame. After the DTIM beacon frame, the first critical update flag signaling is reset to the second value.

Alternatively, the first critical update flag signaling may be redefined as indicating that channel information in the RNR element related to another AP in the first AP multilink device is changed, or indicating that a critical parameter update value of another AP is changed, or indicating that a critical parameter update value of the first AP is changed.

For example, when the first critical update flag signaling indicates channel information of another AP in the first AP multilink device in the RNR element, the first critical update flag signaling may be set to a first value, for example, 1; or when the critical parameter update value of another AP in the first AP multilink device changes, the first critical update flag signaling may be set to a first value, for example, 1; or when the critical parameter update value of the first AP changes, the first critical update flag signaling may be set to a first value, for example, 1. Otherwise, the first critical update flag signaling is set to a second value, for example, 0. It should be noted that if the first critical update flag signaling is set to a first value, the value needs to be maintained until the next DTIM beacon frame. After the DTIM beacon frame, the first critical update flag signaling is reset to the second value.

Alternatively, the first critical update flag signaling may be redefined as indicating that information about another AP in the first AP multilink device (e.g., including one or more of channel information, critical parameter update values, and link identifiers) in the RNR element is changed, or indicating that information about the first AP (e.g., including one or more of critical parameter update values and link identifiers) is changed. It may also be described as the first critical update flag signaling being redefined as indicating that information about another AP in the first AP multilink device is changed (or described as reconfiguration of information about another AP in the first AP multilink device), or indicating that a critical parameter update value of another AP is changed, or indicating that a critical parameter update value of the first AP is changed.

It should be noted that information about another AP in the first AP multilink device (or described as reconfiguration information) may be carried in a management frame, which carries the RNR element.

The link identifier of one AP in the first AP multilink device may be reconfigured, for example, the link identifier of the AP is changed. Of course, the first critical update flag signaling may be another independent signaling, and is carried in a beacon frame, a probe response frame, or another management frame, for example, in a capability information field. In this case, the independent signaling no longer includes a change in the critical parameter update value in the information about another AP in the first AP multilink device, and no longer includes a change in the information about the first AP. In other words, the meaning of the existing first critical update flag signaling is not included.

The change (or reconfiguration) of information about the APs in the first AP multilink device can be understood as one or more of the following:

1. One or more APs are removed from the first multilink device.

For example, the information about the AP does not appear in the RNR element, including the case where the link identifier in the information about the AP is removed. For details, refer to the information shown in Figures 2 and 3. This belongs to one type of change in the information about the AP.

2. One or more APs are added to the first multilink device.

For example, information about an AP is newly added to the RNR element, including the case where a link identifier in the information about an AP is added. For details, refer to the information shown in Figures 2 and 3. This belongs to a kind of change in the information about an AP.

3. A status change between disable/enable states in which one or more APs in the first multilink device resides is a type of change in information about the APs.

For example, one bit of information signaling included in the information about the AP indicates whether the AP is in a disabled or enabled state.

(1) The 1-bit information may be in the MLD parameter field in the RNR element, more specifically, in the link identifier field of the MLD parameter field. The link identifier field includes a 4-bit link identifier and a 1-bit information signaling field, and the 1-bit information signaling field indicates whether the reported AP is in an enabled state or a disabled state. The 1-bit information signaling field is set to a first value, for example, 0, to indicate that the reported AP is in an enabled state, and the 1-bit information signaling field is set to a second value, for example, 1, to indicate that the reported AP is in a disabled state. Alternatively, the 1-bit information signaling field is set to a first value, for example, 1, to indicate that the reported AP is in an enabled state, and the 1-bit information signaling field is set to a second value, for example, 0, to indicate that the reported AP is in a disabled state. Since the MLD parameter field is newly added in the 802.11be standard, the legacy station cannot identify the newly added MLD parameter field and therefore cannot know its meaning.

As an alternative, (2) one bit of information can be in the TBTT information field type in the TBTT information header field in the RNR element. For example, if the TBTT information field type field is set to "0", the AP is in the enabled state, and if the TBTT information field type field is set to another value, for example "1", the AP is in the disabled state. It should be noted that currently, in the RNR element, only the value of 0 is used for the two-bit TBTT information field type field, and the other three values are neither used nor reserved. In this case, the TBTT information field type field is set to another value to indicate that the reported AP is in the disabled state. The value of "0" is still reserved to indicate that the reported AP is in the enabled state. In this way, the conventional station does not identify information about the reported AP. The conventional station does not scan for the reported AP and does not associate with the reported AP. This solves the problem of legacy stations. Legacy stations include unassociated stations and, of course, associated stations.

Alternatively, (3) 1-bit information may be in a reserved field in the TBTT information header field in the RNR element. The 1-bit information is set to a first value, e.g., 0, to indicate that the AP being reported is in an enabled state, and the 1-bit information is set to a second value, e.g., 1, to indicate that the AP being reported is in an disabled state. Alternatively, the 1-bit information is set to a first value, e.g., 1, to indicate that the AP being reported is in an enabled state, and the 1-bit information is set to a second value, e.g., 0, to indicate that the AP being reported is in an disabled state. According to this method, the legacy station does not identify information about the AP being reported. Therefore, the legacy station does not scan the AP being reported, and does not associate with the reporting AP. This solves the problem of the legacy station. The legacy station includes a non-associated station, and of course also includes an associated station.

Of course, methods (1), (2), and (3) are all applicable to new generation 802.11be stations or next generation stations.

4. The operating link (e.g., corresponding channel number or operating class) of one or more APs in the first multilink device is changed.

For example, channel information including the channel number and/or operating class of the AP is changed. Optionally, it further includes changing the link identifier of the AP. This belongs to one type of change in information about the AP.

For example, when the first critical update flag signaling indicates information about another AP in the first AP multilink device in the RNR element (e.g., including channel information, critical parameter update values, and link identifiers), the first critical update flag signaling may be set to a first value, e.g., 1, or when the information about the first AP (e.g., including critical parameter update values and link identifiers) changes, the first critical update flag signaling may be set to a first value, e.g., 1. Otherwise, the first critical update flag signaling is set to a second value, e.g., 0. It should be noted that if the first critical update flag signaling is set to a first value, the value needs to be maintained until the next DTIM beacon frame. After the DTIM beacon frame, the first critical update flag signaling is reset to the second value.

Based on the above redefinition of the first critical update flag signaling, when the critical parameter update value of the AP in the first AP multilink device changes or another AP in the first AP multilink device performs channel switching, the first STA may further analyze the RNR element in the management frame in which the first critical update flag signaling is located to further determine whether another AP in the first AP multilink device performs channel switching. If another AP performs channel switching, the STA obtains channel switching information of the AP that performed channel switching, so that the STA that belongs to the same STA multilink device as the first STA and is associated with the AP that performed channel switching obtains the channel switching information. The first STA may further analyze the management frame to determine whether the critical parameter update value of the AP changes. Alternatively, after receiving the management frame that includes the first critical update flag signaling and is transmitted by the first AP, the first STA may analyze the management frame. Based on the first critical update flag signaling in the management frame, the STA multilink device may obtain changed information of another AP, or a changed critical parameter update value of another AP, or a changed critical parameter update value of the first AP.

Furthermore, similar to the above-mentioned redefinition of the first critical update flag signaling, the above-mentioned second critical update flag signaling may also be redefined. In other words, the second critical update flag signaling indicates whether a critical parameter update value of an AP in the second AP multilink device changes or whether another AP in the second AP multilink device has performed a channel switch.

For example, when the critical parameter update value of an AP in the second AP multilink device changes, the second critical update flag signaling may be set to a first value, for example, 1; or when another AP in the second AP multilink device performs a channel switch, the second critical update flag signaling may be set to a first value, for example, 1; or when the critical parameter update value of an AP in the second AP multilink device changes and the channel of another AP in the second AP multilink device changes, the second critical update flag signaling may be set to a first value, for example, 1. Otherwise, the second critical update flag signaling is set to a second value, for example, 0. It should be noted that if the second critical update flag signaling is set to a first value, the value needs to be maintained until the next DTIM beacon frame. After the DTIM beacon frame, the second critical update flag signaling is reset to the second value.

Alternatively, the second critical update flag signaling may be redefined as indicating that the channel information in the RNR element for another AP in the second AP multilink device other than the transmitting AP is changed, or indicating that the critical parameter update value of another AP is changed, or indicating that the critical parameter update value of the non-transmitting AP is changed.

For example, when the second critical update flag signaling indicates channel information of another AP in the second AP multilink device other than the transmitting AP in the RNR element, the second critical update flag signaling may be set to a first value, for example, 1; or when the critical parameter update value of another AP in the second AP multilink device changes, the second critical update flag signaling may be set to a first value, for example, 1; or when the critical parameter update value of the non-transmitting AP in the second AP multilink device changes, the second critical update flag signaling may be set to a first value, for example, 1. Otherwise, the second critical update flag signaling is set to a second value, for example, 0. It should be noted that if the second critical update flag signaling is set to a first value, the value needs to be maintained until the next DTIM beacon frame. After the DTIM beacon frame, the second critical update flag signaling is reset to the second value.

Alternatively, the second critical update flag signaling may be redefined as indicating that information about another AP in the second AP multilink device other than the transmitted AP (e.g., including one or more of channel information, critical parameter update values, and link identifiers) in the RNR element is changed, or indicating that information about the non-transmitted AP (e.g., including one or more of critical parameter update values and link identifiers) is changed. It may also be described as the second critical update flag signaling being redefined as indicating that information about another AP in the second AP multilink device other than the transmitted AP is changed (or described as reconfiguration of information about another AP in the second AP multilink device other than the transmitted AP), or indicating that a critical parameter update value of another AP is changed, or indicating that a critical parameter update value of a non-transmitted AP is changed. It should be noted that information about another AP in the second AP multilink device other than the transmitted AP (or described as reconfiguration information) may be carried in a management frame, and the management frame carries the RNR element.

Of course, the second important update flag signaling may be other independent signaling, carried in a beacon frame, a probe response frame, or another management frame, and is located, for example, in an untransmitted BSSID capability information field (in an untransmitted BSSID capability field in an untransmitted BSSID capability element in a multi-BSSID element). In this case, the independent signaling no longer includes a change in an important parameter update value in the information about another AP in the second AP multilink device, and no longer includes a change in the information about the second AP. In other words, the meaning of the existing second important update flag signaling is not included.

The change (or reconfiguration) of information about the AP in the second AP multilink device may be understood as one or more of the following:

1. One or more APs are removed from the second multilink device.

For example, the information about the AP does not appear in the RNR element, including the case where the link identifier in the information about the AP is removed. For details, refer to the information shown in Figures 2 and 3. This belongs to one type of change in the information about the AP.

2. One or more APs are added to the second multilink device.

For example, information about an AP is newly added to the RNR element, including the case where a link identifier in the information about an AP is added. For details, refer to the information shown in Figures 2 and 3. This belongs to one type of change in the information about an AP.

3. A status change between disable/enable states in which one or more APs in the second multilink device resides is a type of change in information about the APs.

For example, one bit of information signaling included in the information about the AP indicates whether the AP is in a disabled or enabled state.

(1) The 1-bit information may be in the MLD parameter field in the RNR element, more specifically, in the link identifier field of the MLD parameter field. The link identifier field includes a 4-bit link identifier and a 1-bit information signaling field, and the 1-bit information signaling field indicates whether the reported AP is in an enabled state or a disabled state. The 1-bit information signaling field is set to a first value, for example, 0, to indicate that the reported AP is in an enabled state, and the 1-bit information signaling field is set to a second value, for example, 1, to indicate that the reported AP is in a disabled state. Alternatively, the 1-bit information signaling field is set to a first value, for example, 1, to indicate that the reported AP is in an enabled state, and the 1-bit information signaling field is set to a second value, for example, 0, to indicate that the reported AP is in a disabled state. Since the MLD parameter field is newly added in the 802.11be standard, the legacy station cannot identify the newly added MLD parameter field and therefore cannot know its meaning.

As an alternative, (2) one bit of information can be in the TBTT information field type in the TBTT information header field in the RNR element. For example, if the TBTT information field type field is set to "0", the AP is in the enabled state, and if the TBTT information field type field is set to another value, for example "1", the AP is in the disabled state. It should be noted that currently, in the RNR element, only the value of 0 is used for the two-bit TBTT information field type field, and the other three values are neither used nor reserved. In this case, the TBTT information field type field is set to another value to indicate that the reported AP is in the disabled state. The value of "0" is still reserved to indicate that the reported AP is in the enabled state. In this way, the conventional station does not identify information about the reported AP. The conventional station does not scan for the reported AP and does not associate with the reported AP. This solves the problem of legacy stations. Legacy stations include unassociated stations and, of course, associated stations.

Alternatively, (3) 1-bit information may be in a reserved field in the TBTT information header field in the RNR element. The 1-bit information is set to a first value, e.g., 0, to indicate that the AP being reported is in an enabled state, and the 1-bit information is set to a second value, e.g., 1, to indicate that the AP being reported is in an disabled state. Alternatively, the 1-bit information is set to a first value, e.g., 1, to indicate that the AP being reported is in an enabled state, and the 1-bit information is set to a second value, e.g., 0, to indicate that the AP being reported is in an disabled state. According to this method, the legacy station does not identify information about the AP being reported. Therefore, the legacy station does not scan the AP being reported, and does not associate with the reporting AP. This solves the problem of the legacy station. The legacy station includes a non-associated station, and of course also includes an associated station.

Of course, methods (1), (2), and (3) are all applicable to new generation EHT stations or next generation stations.

4. The operating link (e.g., corresponding channel number or operating class) of one or more APs in the second multilink device is changed.

For example, channel information including the channel number and/or operating class of the AP is changed. Optionally, it further includes changing the link identifier of the AP. This belongs to one type of change in information about the AP.

For example, when the second critical update flag signaling indicates information (e.g., including channel information, critical parameter update values, and link identifiers) about another AP in the second AP multilink device other than the transmitting AP in the RNR element, the second critical update flag signaling may be set to a first value, e.g., 1, or when the information (e.g., including critical parameter update values and link identifiers) about the non-transmitting AP changes, the second critical update flag signaling may be set to a first value, e.g., 1. Otherwise, the second critical update flag signaling is set to a second value, e.g., 0. It should be noted that if the second critical update flag signaling is set to a first value, the value needs to be maintained until the next DTIM beacon frame. After the DTIM beacon frame, the second critical update flag signaling is reset to the second value.

Based on the above redefinition of the second critical update flag signaling, when the critical parameter update value of the AP in the second AP multilink device changes or another AP in the second AP multilink device performs channel switching, the first STA may further analyze the RNR element in the management frame in which the second critical update flag signaling is located to further determine whether another AP in the second AP multilink device performs channel switching. If another AP performs channel switching, the STA obtains channel switching information of the AP that performed channel switching, so that the STA that belongs to the same STA multilink device as the first STA and is associated with the AP that performed channel switching obtains the channel switching information. The first STA may further analyze the management frame to determine whether the critical parameter update value of the AP changes. Alternatively, after receiving the management frame that includes the second critical update flag signaling and is transmitted by the first AP, the first STA may analyze the management frame. Based on the second critical update flag signaling in the management frame, the STA multilink device may obtain the changed information of another AP, or the changed critical parameter update value of another AP, or the changed critical parameter update value of a non-transmitting AP.

Corresponding to whether the AP has performed channel switching being determined based on the first indication information, an embodiment of the present application further provides a communication method, as shown in FIG. 13. As shown in FIG. 13, the method may include the following steps:

Step 1301: The first AP generates a management frame.

The management frame may include a multi-link (ML) element. After another AP in the first AP multi-link device performs a channel switch, the ML element may include channel switch information of the AP that performed the channel switch, and the ML element is until the next broadcast DTIM beacon frame transmitted by the first AP. Alternatively, after an AP in the first AP multi-link device including the first AP performs a channel switch, the ML element may include channel switch information of the AP that performed the channel switch, and the ML element is until the next broadcast DTIM beacon frame transmitted by the first AP.

The following uses an example in which, after another AP in the first AP multilink device performs a channel switch, the ML element may include channel switch information of the AP that performed the channel switch, and the ML element is until the next delivery DTIM beacon frame sent by the first AP. It can be understood that the following embodiment is also applicable to the case in which, after an AP in the first AP multilink device including the first AP performs a channel switch, the ML element may include channel switch information of the AP that performed the channel switch, and the ML element is until the next delivery DTIM beacon frame sent by the first AP.

For example, as shown in FIG. 14, an ML element may include an element identifier field, a length field, an element ID extension field, a multilink control field, a common information field, and a link information field.

The link information field may include several per-STA profile fields. Each per-STA profile field may include a subelement ID field, a length field, a STA control field, a STA information field, and a STA profile field.

It should be noted that the Extended Channel Switching element in the STA Profile field and the Operation Class field and Channel Number field in the STA Information field in Figure 14 correspond separately to the following two possible designs and do not appear simultaneously. The details are as follows:

In a possible design, the channel switching information is an element related to channel switching, and the first AP adds an element related to channel switching to the STA profile field in the ML element.

The channel switch elements may include a channel switch element or an extended channel switch element that is used to indicate that the reporting AP has performed a channel switch until the next DTIM beacon frame.

The channel switch element further includes a channel switch count field. The channel switch count field indicates the amount of TBTT before a station transmitting a channel switch element or transmitting an extended channel switch element switches to a new channel or switches to a new operating class and new channel. When the value of the channel switch count field is a first value, e.g., 1, the channel switch count field may indicate that a channel switch occurs immediately before the next target beacon transmission time. When the value of the channel switch count field is a second value, e.g., 0, the channel switch count field may indicate that a channel switch occurs any time after a management frame is transmitted or that a channel switch has occurred.

For example, when another AP in the first AP multilink device performs a channel switch, and when the first AP transmits a management frame after the AP completes the channel switch, the channel switch-related elements of the AP performing the channel switch are still carried in the STA profile field in the ML element in the management frame until the next DTIM beacon frame, so that the first STA obtains the channel switch-related elements of the AP that performed the channel switch based on the management frame. Thus, STAs that belong to the same STA multilink device as the first STA and are associated with the AP that performed the channel switch obtain the channel switch-related elements. In this case, in the channel switch-related elements, the value of the channel switch count field may be a second value, e.g., 0, to indicate that the channel switch occurs at any time after the management frame is transmitted, or that the channel switch has occurred.

In yet another possible design, the channel switching information is channel information, and the first AP conveys the channel information in a STA information field in the ML element.

The channel information may include an operating class and a channel number, or the channel information may include a channel number.

For example, when another AP in the first AP multilink device performs a channel switch, and when the first AP transmits a management frame after the AP completes the channel switch, the channel information of the AP performing the channel switch is still carried in the STA information field in the ML element in the management frame until the next DTIM beacon frame, so that the first STA obtains the channel information of the AP that performed the channel switch based on the management frame. Therefore, STAs that belong to the same STA multilink device as the first STA and are associated with the AP that performed the channel switch obtain the channel information.

Step 1302: The first AP transmits a management frame to the first station STA. In response, the first STA receives the management frame.

Step 1303: The first STA obtains channel switching information based on the ML element, whereby a STA that belongs to the same STA multilink device as the first STA and is associated with the AP that performs channel switching obtains the channel switching information.

In a possible design, the first STA parses the STA profile field in the ML element in the management frame (e.g., DTIM beacon frame) to obtain channel switching-related elements of the AP in the first AP multilink device that performed the channel switch. In this way, STAs that belong to the same STA multilink device as the first STA and are associated with the AP that performed the channel switch obtain the channel switching-related elements. In this case, in the channel switching-related elements, the value of the channel switching count field may be a second value to indicate that the channel switching occurs at any time after the management frame is transmitted or that the channel switching has occurred.

In another possible design, the first STA parses the STA information field in the ML element in the management frame (e.g., DTIM beacon frame) to obtain channel information of the AP in the first AP multilink device that performed the channel switch. In this way, STAs that belong to the same STA multilink device as the first STA and are associated with the AP that performed the channel switch obtain the channel information.

For example, as shown in FIG. 15, the STA multilink device includes STA1 and STA2, and establishes a multilink connection to the first AP multilink device, and STA1 and STA2 are associated with AP1 and AP2 in the first AP multilink device, respectively. It is assumed that STA1 is in a dormant state, STA2 observes link 2 on which STA2 operates, and STA2 only wakes up at the time of a DTIM beacon frame in link 2. After AP1 performs a channel switch, because the interval between beacon frames transmitted by AP2 in link 2 is large, AP2 may carry channel switch information in the ML element in the second beacon frame and the third beacon frame (which are the first TIM beacon frame and the second DTIM beacon frame in FIG. 15, respectively) in link 2. STA2 may analyze the ML element in the DTIM beacon frame received in link 2 to know that AP1 in link 1 has performed a channel switch, and learn about the channel switch information. In this way, STA1 associated with AP1 obtains the channel switching information of AP1, thereby ensuring that STA1 can communicate normally with AP1.

Optionally, if the first AP is in the multi-BSSID set and the first AP is the transmitting AP, the ML element in the transmitted management frame may further include channel switch information of another AP in the second AP multi-link device that performed the channel switch, and the ML element is until the first STA receives the next DTIM beacon frame transmitted by the first AP.

The other AP in the second AP multilink device may be another AP in the second multilink device other than the transmitting AP.

In a possible design, when another AP in the second AP multilink device performs a channel switch, and when the first AP transmits a management frame after the AP completes the channel switch, the channel switch-related element of the AP in the second AP multilink device that performs the channel switch is still carried in the STA profile field in the ML element in the management frame until the next DTIM beacon frame, so that the first STA obtains the channel switch-related element of the AP that performed the channel switch based on the management frame. Thus, a STA that belongs to the same STA multilink device as the first STA and is associated with the AP that performed the channel switch obtains the channel switch-related element. In this case, in the channel switch-related element, the value of the channel switch count field may be a second value to indicate that the channel switch occurs at any time after the management frame is transmitted, or that the channel switch has occurred.

In another possible design, when another AP in the second AP multilink device performs a channel switch, and when the first AP transmits a management frame after the AP completes the channel switch, the channel information of the AP in the second AP multilink device that performs the channel switch is still carried in the STA information field in the ML element in the management frame until the next DTIM beacon frame, so that the first STA obtains the channel information of the AP that performed the channel switch based on the management frame. Thus, the STAs that belong to the same STA multilink device as the first STA and are associated with the AP that performed the channel switch obtain the channel information.

Based on the method depicted in FIG. 13, when the first AP transmits a management frame, the ML element in the management frame carries the channel switch information of the AP that performed the channel switch in the first AP multilink device or the second AP multilink device. In this way, the first STA associated with the first AP can determine the channel switch information of the AP that performed the channel switch based on the ML element. Furthermore, the STA that belongs to the same STA multilink device as the first STA and is associated with the AP that performed the channel switch knows that the AP associated with the STA performed the channel switch, and knows about the channel switch information after the channel switch.

The above mainly describes the solutions provided in the embodiments of this application from the perspective of interactions between devices. It can be understood that in order to realize the aforementioned functions, the devices include hardware structures and/or software modules corresponding to the functions. In combination with the algorithms and steps in the examples described in the embodiments disclosed in this specification, those skilled in the art should easily recognize that this application can be realized by hardware, or a combination of hardware and computer software. Whether the functions are performed by hardware or by hardware driven by computer software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to realize the functions described for each specific application, but the implementation should not be considered to go beyond the scope of this application.

In the embodiment of this application, each device may be divided into functional modules based on the above-mentioned method examples. For example, functional modules corresponding to various functions may be obtained through division, or two or more functions may be integrated into one processing module. The integrated module may be implemented in the form of hardware or in the form of a software functional module. It should be noted that in the embodiment of this application, the division of modules is an example and is merely a logical functional division. In actual implementation, another division method may be used.

Figure 16 represents the first AP when each functional module is obtained through division based on each corresponding function. The first AP 160 may include a processing module 1601 and a transceiver module 1602. For example, the first AP 160 may be the first AP, or may be a chip used in the first AP, or another combination of components, parts, or the like having the functionality of the first AP. When the first AP 160 is the first AP, the processing module 1601 may be a processor (or processing circuit), for example, a baseband processor. The baseband processor may include one or more CPUs. The transceiver module 1602 may be a transceiver. The transceiver may include an antenna, a radio frequency circuit, and the like. When the first AP 160 is a component having the functionality of the first AP, the processing module 1601 may be a processor (or processing circuit), for example, a baseband processor, and the transceiver 1602 may be a radio frequency unit. When the first AP 160 is a chip system, the processing module 1601 may be a processor (or processing circuit) of the chip system and may include one or more central processing units. The transceiver module 1602 may be an input/output interface of a chip (e.g., a baseband chip). It should be understood that the processing module 1601 in this embodiment of the application may be implemented by a processor or a processor-related circuit component (or called a processing circuit), and the transceiver module 1602 may be implemented by a transceiver or a transceiver-related circuit component.

For example, the processing module 1601 may be configured to perform all operations other than the receiving and transmitting operations performed by the first AP in the embodiments depicted in Figures 8 to 15 and/or to support other processes of the techniques described in this specification. The transceiver module 1602 may be configured to perform all the receiving and transmitting operations performed by the first AP in the embodiments depicted in Figures 8 to 15 and/or to support other processes of the techniques described in this specification.

In yet another possible implementation, the processing module 1601 in FIG. 16 may alternatively be a processor, and the functions of the processing module 1601 may be integrated into the processor. The transceiver module 1602 may alternatively be a transceiver, and the functions of the transceiver module 1602 may be integrated into the transceiver. Furthermore, the first AP 160 depicted in FIG. 16 may further include a memory. When the processing module 1601 is replaced by a processor and the transceiver module 1602 is replaced by a transceiver, the first AP 160 in this embodiment of the application may be the communication device depicted in FIG. 7.

Figure 17 represents the first STA when each functional module is obtained through division based on each corresponding function. The first STA 170 may include a transceiver module 1701 and a processing module 1702. For example, the first STA 170 may be the first STA, or may be a chip used in the first STA, or another combination of components, parts, or the like having the functionality of the first STA. When the first STA 170 is the first STA, the transceiver module 1701 may be a transceiver, which may include an antenna, a radio frequency circuit, and the like, and the processing module 1702 may be a processor (or processing circuit), e.g., a baseband processor, which may include one or more CPUs. When the first STA 170 is a component having the functionality of the first STA, the transceiver module 1701 may be a radio frequency unit, and the processing module 1702 may be a processor (or processing circuit), e.g., a baseband processor. When the first STA 170 is a chip system, the transceiver module 1701 may be an input/output interface of a chip (e.g., a baseband chip), and the processing module 1702 may be a processor (or processing circuit) of the chip system and may include one or more central processing units. It should be understood that the transceiver module 1701 in this embodiment of the application may be implemented by a transceiver or a transceiver-related circuit component, and the processing module 1702 may be implemented by a processor or a processor-related circuit component (or referred to as a processing circuit).

For example, the transceiver module 1701 may be configured to perform all receive and transmit operations performed by the first STA in the embodiments depicted in Figures 8 to 15 and/or to support other processes of the techniques described in this specification. The processing module 1702 may be configured to perform all operations other than receive and transmit operations performed by the first STA in the embodiments depicted in Figures 8 to 15 and/or to support other processes of the techniques described in this specification.

In yet another possible implementation, the transceiver module 1701 in FIG. 17 may be replaced by a transceiver, and the functions of the transceiver module 1701 may be integrated into the transceiver. The processing module 1702 may be replaced by a processor, and the functions of the processing module 1702 may be integrated into the processor. Furthermore, the first STA 170 depicted in FIG. 17 may further include a memory. When the transceiver module 1701 is replaced by a transceiver and the processing module 1702 is replaced by a processor, the first STA 170 in this embodiment of the application may be the communication device depicted in FIG. 7.

The embodiment of this application further provides a computer-readable storage medium. All or some of the processes in the aforementioned method embodiments may be implemented by a computer program instructing associated hardware. The program may be stored in a computer-readable storage medium. When the program is executed, the processes of the aforementioned method embodiments may be included. The computer-readable storage medium may be an internal storage unit of the terminal (including the data sending end and/or the data receiving end) in any one of the aforementioned embodiments, such as a hard disk drive or memory of the terminal. Alternatively, the computer-readable storage medium may be an external storage device of the terminal, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, or the like, configured in the terminal. Furthermore, the computer-readable storage medium may alternatively include both the internal storage unit and the external storage device of the terminal. The computer-readable storage medium is configured to store the computer program and other programs and data required by the terminal. The computer-readable storage medium may further be configured to temporarily store data that has been output or is to be output.

It should be noted that in the specification, claims, and accompanying drawings of this application, the terms "first," "second," and the like are intended to distinguish between different objects, but do not indicate a particular order. In addition, the terms "comprise" and "have," as well as any other variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the recited steps or units, but may optionally further include unrecited steps or units, or may optionally further include another inherent step or unit of the process, method, product, or device.

It should be noted that in the specification, claims, and accompanying drawings of this application, the names of the newly provided fields compared to the 802.11-2016 protocol and the 802.11ax Draft 8.0 protocol may be different names. This is not limited.

In this application, "at least one item" means one or more, "multiple" or "a plurality of" means two or more, "at least two items" means two, three, or more, and "and/or" is used to describe an association relationship between associated objects and should be understood to indicate that there may be three relationships. For example, "A and/or B" may indicate that only A is present, that only B is present, and that both A and B are present, where A and B may be singular or plural. The character "/" generally indicates an "or" relationship between associated objects. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of singular items or multiple items. For example, at least one of a, b, or c may refer to a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c may be singular or plural.

The above description of the implementation allows those skilled in the art to understand that for the purpose of convenient and simple description, the division of the above-mentioned functional modules is taken as an illustrative example. During actual application, the above-mentioned functions can be allocated to different modules and implemented according to requirements, that is, the internal structure of the device is divided into different functional modules to realize all or some of the functions described above.

In some embodiments provided in this application, it should be understood that the disclosed apparatus and method may be realized in other manners. For example, the described apparatus embodiments are merely examples. For example, the division into modules or units is merely a logical division of function, and may be other divisions in actual implementation. For example, multiple units or components may be combined or integrated into another apparatus, or some features may be ignored or not implemented. In addition, the mutual couplings or direct couplings or communication connections shown or discussed may be implemented by using some interfaces. Indirect couplings or communication connections between apparatuses or units may be implemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physically separate, and the parts shown as units may be one or multiple physical units and may be located in one location or distributed in different locations. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solution of the embodiment.

In addition, the functional units in the embodiments of this application may be integrated into one processing unit, each of the units may exist physically alone, or two or more units may be integrated into one unit. The integrated units may be implemented in the form of hardware or in the form of software functional units.

When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, the integrated unit may be stored in a readable storage medium. Based on such understanding, essentially all or some of the technical solutions of this application, or the part that contributes to the prior art, or the technical solutions, may be implemented in the form of a software product. The software product includes some instructions stored in a storage medium to instruct a device (which may be a single-chip microcomputer, chip, or the like) or a processor to execute all or some of the steps of the method described in the embodiments of this application. The aforementioned storage medium includes any medium capable of storing program code, such as a USB flash drive, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

160 First AP
170 1st STA
400 Communication Systems
401 Station
402 Station
500 Communication Systems
600 Communication Systems
601 AP MLD
601-1 to 3 Affiliated MLD
602 STA MLD
601-1 to 3 Affiliated STA
603 STA MLD
603-1, 603-2 Affiliated STA
604 STA
700 Communication Equipment
701 AP MLD, Processor
702 Transceiver
703 Communication Line
704 Memory
705 Output Device
706 Input Devices
707 Processor
1601 Processing Module
1602 Transceiver Module
1701 Transceiver Module
1702 Processing Module

Claims (38)

generating a management frame by a first access point (AP), the management frame including a first critical update flag signaling, the first critical update flag signaling being set to a first value when one or more APs are removed from a first AP multilink device, or one or more APs are newly added to the first AP multilink device, or there is a change in the disabled/enabled status of one or more APs in the first AP multilink device, the first AP multilink device comprising the first AP;
and transmitting, by the first AP, the management frame to a first station (STA). The method of claim 1, wherein the first important update flag signaling is set to the first value when a value of an important parameter update value of an AP in the first AP multilink device changes or an operating link of one or more APs in the first AP multilink device is changed . The method of claim 2, further comprising the step of adjusting, by the first AP, a critical parameter update value of the AP when any event among critical basic service set (BSS) parameter events corresponding to the AP in the first AP multilink device occurs. adjusting, by the first AP, a critical parameter update value of the AP;
The method of claim 3 , further comprising: increasing a critical parameter update value of the AP by one each time a critical BSS parameter event of the AP occurs. 4. The method of claim 3, wherein the critical BSS parameter events include at least one of the following events: an enhanced distributed channel access (EDCA) parameter element is modified, a direct sequence spread spectrum (DSSS) parameter set element is modified, a high throughput (HT) operation element is modified, a wide bandwidth channel switch element is included , a channel switch wrapper element is included, an operation mode notification element is included, an operation element is modified, a high efficiency (HE) operation element is modified, a broadcast target wake time (TWT) element is inserted, a BSS color change announcement element is included, a multi-user (MU) EDCA parameter set element is modified, a spatial reuse parameter set element is modified, and an extremely high throughput (EHT) operation element is modified. The method of claim 2 , wherein the critical parameter update value is a critical basic service set (BSS) parameter change count value. The method of claim 1, wherein the value of the first important update flag signaling is a first value or a second value. The method of claim 1, wherein when the first critical update flag signaling is set to a first value, the first value is maintained until the next DTIM beacon frame. 2. The method of claim 1, wherein the management frame further includes a second important update flag signaling, and the second important update flag signaling indicates that information about another AP in a second AP multilink device other than a non-transmitting AP that belongs to the same multi-basic service set identifier (BSSID) set as the first AP changes, a critical parameter update value of the other AP changes , or a critical parameter update value of a non-transmitting AP in the second AP multilink device that belongs to the same multi-BSSID set as the first AP changes. The information about the other AP changes, including whether the AP is removed from the second AP multilink device;
The information about the other AP changes, including whether an AP is newly added to the second AP multilink device;
The information about the other AP changes includes a change in the disabled/enabled state of one or more APs in the second AP multilink device; or
10. The method of claim 9, wherein the change in information about the other AP comprises a change in an operational link of one or more APs in the second AP multilink device. The method of claim 9, further comprising the step of adjusting, by the first AP, the value of the critical parameter update value of the AP when any event among the critical BSS parameter events corresponding to the AP in the second AP multilink device occurs. adjusting, by the first AP, a critical parameter update value of the AP;
The method of claim 11 , comprising: each time a critical BSS parameter event of the AP occurs, a critical parameter update value of the AP is increased by one. The method of claim 9, wherein the value of the second important update flag signaling is the first value or the second value. The method of claim 9, wherein when the second important update flag signaling is set to a first value, the first value is maintained until the next DTIM beacon frame. receiving a management frame from a first access point (AP) by a first station (STA), the management frame including a first critical update flag signaling, the first critical update flag signaling being set to a first value when one or more APs are removed from a first AP multilink device, or one or more APs are newly added to the first AP multilink device, or there is a change in the disabled/enabled status of one or more APs in the first AP multilink device, the first AP multilink device comprising the first AP, and a STA multilink device comprising the first STA;
and analyzing, by the first STA, the management frame. said step of analyzing said management frame by said first STA further comprising:
The method of claim 15, comprising: obtaining, by the first STA , information about one or more APs in the first AP multilink device based on the first important update flag signaling. The method of claim 15, wherein when a value of a critical parameter update value of an AP in the first AP multilink device changes or an operating link of one or more APs in the first AP multilink device is changed, the first critical update flag signaling is set to the first value . The method of claim 17, wherein the value of the critical parameter update value of the AP in the first AP multilink device is adjusted based on the occurrence of any one of critical basic service set (BSS) parameter events corresponding to the AP. The method of claim 18, wherein each time a critical BSS parameter event occurs for the AP, the critical parameter update value for the AP is increased by 1. 20. The method of claim 18, wherein the critical BSS parameter events include at least one of the following events: an enhanced distributed channel access (EDCA) parameter element is modified, a direct sequence spread spectrum (DSSS) parameter set element is modified, a high throughput (HT) operation element is modified, a wide bandwidth channel switch element is included , a channel switch wrapper element is included, an operation mode notification element is included, a very high throughput (VHT) operation element is modified, a high efficiency (HE) operation element is modified, a broadcast target wake time (TWT) element is inserted, a BSS color change announcement element is included, a multi-user (MU) EDCA parameter set element is modified, a spatial reuse parameter set element is modified, and an extremely high throughput (EHT) operation element is modified. The method of claim 17 , wherein the critical parameter update value is a critical basic service set (BSS) parameter change count value. The method of claim 15, wherein the value of the first important update flag signaling is a first value or a second value. The method of claim 15, wherein when the first critical update flag signaling is set to a first value, the first value is maintained until the next DTIM beacon frame. 16. The method of claim 15, wherein the management frame further includes a second critical update flag signaling, and the second critical update flag signaling indicates that information about another AP in a second AP multilink device other than a non-transmitting AP that belongs to the same multi-basic service set identifier (BSSID) set as the first AP changes, that a critical parameter update value of the other AP changes, or that a critical parameter update value of a non-transmitting AP in the second AP multilink device that belongs to the same multi-BSSID set as the first AP changes. 25. The method of claim 24, further comprising: acquiring, by the first STA, the changed information of the other AP, the changed critical parameter update value of the other AP, or the changed critical parameter update value of the non-transmitting AP based on the second critical update flag signaling. The information about the other AP changes, including whether the AP is removed from the second AP multilink device;
The information about the other AP changes, including whether an AP is newly added to the second AP multilink device;
The information about the other AP changes includes a change in the disabled/enabled state of one or more APs in the second AP multilink device; or
25. The method of claim 24, wherein the change in information about the other AP comprises a change in an operational link of one or more APs in the second AP multilink device. 25. The method of claim 24, wherein the value of the critical parameter update value of the AP in the second AP multilink device is adjusted based on the occurrence of any of the critical BSS parameter events corresponding to the AP. The method of claim 27, wherein each time a critical BSS parameter event occurs for the AP, the critical parameter update value for the AP is increased by 1. 25. The method of claim 24 , wherein the value of the second important update flag signaling is the first value or the second value. 25. The method of claim 24, wherein when the second critical update flag signaling is set to a first value, the first value is maintained until the next DTIM beacon frame. A communication device, the communication device comprising a processor, the processor configured to execute a computer program or instructions to perform a communication method according to any one of claims 1 to 14. A communication device, the communication device comprising a processor, the processor configured to execute a computer program or instructions to perform a communication method according to any one of claims 15 to 30. A communication device comprising a processor and a communication interface, the communication interface coupled to the processor, the processor configured to execute computer programs or instructions to perform the communication method of any one of claims 1 to 14, and the communication interface configured to communicate with a module other than the communication device. A communication device comprising a processor and a communication interface, the communication interface coupled to the processor, the processor configured to execute computer programs or instructions to perform a communication method according to any one of claims 15 to 30, and the communication interface configured to communicate with a module other than the communication device. 15. A communication device, the communication device comprising an interface circuit and a logic circuit, the interface circuit configured to obtain input information and/or output information, and the logic circuit configured to execute a communication method according to any one of claims 1 to 14, performing processing based on the input information and/or generating the output information. 31. A communication device, the communication device comprising an interface circuit and a logic circuit, the interface circuit configured to obtain input information and/or output information, and the logic circuit configured to execute a communication method according to any one of claims 15 to 30 to perform processing based on the input information and/or generate the output information. 15. A computer readable storage medium having computer instructions or programs stored therein, the computer readable storage medium performing the communication method according to any one of claims 1 to 14 when the computer instructions or programs are executed or run on a computer. 31. A computer readable storage medium having computer instructions or programs stored therein, the computer readable storage medium performing the communication method of any one of claims 15 to 30 when the computer instructions or programs are executed or run on a computer.